Path1.txt

A 56-year-old has not received any medical care nor seen a physician for years. He reports reduced exercise tolerance over the past 5 years. On occasion in the past year he has noted chest pain after ascending a flight of stairs. He smokes 2 packs of cigarettes per day. He is found to have a blood pressure of 155/95 mm Hg. His body mass index is 30. Laboratory findings include a total serum cholesterol of 245 mg/dL with an HDL cholesterol that is 22 mg/dL. Which of the following vascular abnormalities is most likely to be his most serious health risk?

A 55-year-old previously healthy woman is hospitalized for pneumonia. On the 10th hospital day she is found to have swelling and tenderness of her right leg, which apparently has developed over the past 48 hours. Raising the leg elicits pain. An ultrasound examination reveals findings suggestive of femoral vein thrombosis. Which of the following conditions is most likely to have contributed the most to the appearance of these findings?

A 63-year-old man has had insulin dependent diabetes mellitus for over two decades. The degree of control of his disease is characterized by the laboratory finding of a hemoglobin A1C of 10.1%. He has noted episodes of abdominal pain following meals. These episodes have worsened over the past year. On physical examination, there are no masses and no organomegaly of the abdomen, and he has no tenderness to palpation. Which of the following pathologic findings is most likely to be present in this man?

A 62-year-old man has experienced substernal chest pain upon exertion with increasing frequency over the past 6 months. An electrocardiogram shows features consistent with ischemic heart disease. He has a total serum cholesterol of 262 mg/dL. By angiography, there is 75% narrowing of the left anterior descending artery. Which of the following vascular complications is most likely to occur in this patient?

On sectioning of an organ from a 60-year-old man at the time of autopsy, a focal, wedge-shaped area that is firm is accompanied by extensive hemorrhage, giving it a red appearance. The lesion has a base on the surface of the organ. In which of the following situations will this lesion most likely occur?

A 44-year-old woman has a family history of heart disease. Her father and mother both developed congestive heart failure and myocardial infarction as a result of extensive coronary atherosclerosis. A dietary modification to include consumption of which of the following is most likely to reduce her risk for ischemic heart disease?

An 81-year-old woman has the sudden onset of dyspnea and palpitations with chest pain. A pulmonary ventilation-perfusion scan is performed and indicates a high probability for a perfusion defect involving right segmental pulmonary arterial branch. Of the following findings or conditions, which is the most important factor favoring development of these findings?

A 66-year-old woman has the sudden loss of movement on part of the left side of her body. She has smoked a pack of cigarettes a day for the past 45 years. She has vital signs including T 37.1 C, P 80/minute, RR 16/minute, and BP 160/100 mm Hg. A cerebral angiogram reveals occlusion of a branch of her middle cerebral artery. Laboratory findings include a hemoglobin A1C of 9%. Which of the following components of blood lipids is most important in contributing to her disease?

An autopsy study reveals that evidence for atheroma formation can begin even in children. The gross appearances of the aortas are recorded and compared with microscopic findings of atheroma formation. Which of the following is most likely to be the first visible gross evidence for the formation of an atheroma?

A 63-year-old man has had increasing exercise intolerance for the past 5 years so that he now becomes short of breath upon climbing a single flight of stairs. Laboratory studies have shown fasting blood glucose measurements from 145 to 210 mg/dL for the past 25 years, but he has not sought medical treatment. If he dies suddenly, which of the following is most likely to be the immediate cause of death?

A 45-year-old man dies suddenly and unexpectedly. The immediate cause of death is found to be a hemorrhage in the right basal ganglia region. On microscopic examination his renal artery branches have concentric endothelial cell proliferation which markedly narrows the lumen, resulting in focal ischemia and hemorrhage of the renal parenchyma. An elevation in which of the following substances in his blood is most likely to be associated with these findings?

A 10-year-old previously healthy child has been noted by her parents to be constantly thirsty. She is consuming large amounts of soft drinks. She is urinating often. Her diet and exercise patterns have not changed, except for an increased appetite, yet she appears cachectic and has lost 7 kg over the past 4 months. On physical examination there are no abnormal findings, other than peripheral muscle wasting and weakness. Which of the following laboratory findings would you most strongly suspect is present in this girl?

A 73-year-old woman who exercises regularly falls down the stairs and injures her right hip. A radiograph is taken of the pelvis. There is no fracture but the radiograph reveals calcification of the small muscular arteries lateral to her uterus. What is the probable vascular lesion which accounts for this calcification?

A 55-year-old woman has been treated in the hospital for pancreatitis for the past three weeks. She is examined one morning on rounds and found to have a swollen right leg. It is tender to palpation posteriorly but is not warm. This condition is most likely to be the result of which of the following vascular complications?

A 29-year-old woman is involved in a motor vehicle accident that results in severe lacerations to her lower extremities, along with blunt abdominal trauma. In the emergency room she is noted to have cool, pallid skin. She has vital signs showing T 36.9 C, P 103/minute, RR 18/minute, and BP 70/30 mm Hg. She has decreased urine output. Which of the following laboratory findings on a blood sample from this patient is most likely to be present?

A 61-year-old man has the sudden onset of severe chest pain. Vital signs include T 37 C, P 101/minute, RR 20/minute, and BP 80/40 mm Hg. An electrocardiogram demonstrates changes that are consistent with myocardial ischemia involving the left lateral ventricular free wall. He is given thrombolytic therapy with tissue plasminogen activator (tPA). However his serum creatinine kinase is found to be 450 U/L 3 hours after this therapy. Which of the following cellular events has most likely occurred?

A 52-year-old woman has experienced marked substernal, crushing chest pain for the past 6 hours. Her vital signs show T 36.9 C, P 80/minute, RR 16/minute, and BP 100/60 mm Hg. Laboratory studies include a serum creatine kinase MB fraction of 10 microgm/L as well as a serum troponin I of 4.5 ng/mL. Which of the following findings is the best evidence for the presence of a coronary arterial thrombus as the etiology for her chest pain?

In an experiment, a glass bead is embolized to a branch of the renal artery. A day later there is a focal area in which the renal parenchymal cells in the distribution of the occluded artery show karyolysis and karyorrhexis. The outlines of the cells are still visible, but the nuclei have lost basophilic staining and the cytoplasm is eosinophilic but pale. Which of the following types of cellular necrosis is most likely present?

A 52-year-old man has the sudden onset of chest pain. He is found to have a serum troponin I of 5 ng/mL. A year later he has reduced exercise tolerance. An echocardiogram reveals an akinetic segment of left ventricle, and he has reduced cardiac output, with an ejection fraction of 25%. He then experiences a transient ischemic attack (TIA). His serum troponin I is now <0.5 ng/mL. Thrombus formation involving which of the following locations is most likely to have put him at greatest risk for the TIA?

A 25-year-old previously healthy primigravida is in the first trimester of pregnancy. During two successive prenatal visits, she has fasting serum glucose levels of 127 and 131 mg/dL. Prior to this pregnancy, her fasting serum glucose was 80 mg/dL. A hemoglobin A1C level is 8.1% at the last visit, at 18 weeks gestation. She feels well and has no major health problems. Which of the following problems is most likely to become apparent in the latter part of her pregnancy?

A 54-year-old man with diabetes mellitus has had 3 urinary tract infections during the past year. He now sees the physician for an ulceration on his right big toe which has not healed in 2 months. Laboratory studies on each of his doctor visits over the past year show blood glucose levels below 110 mg/dl. This situation could be best explained by which of the following laboratory findings?

A 25-year-old man experiences chest pain on exercise when he attempts to climb three flights of stairs. This pain is relieved by sublingual nitroglycerin. He is 178 cm tall and weighs 101 kg. Laboratory studies show a total serum cholesterol of 550 mg/dL with an HDL cholesterol component of 25 mg/dL. He is worried about these findings because his brother died of a myocardial infarction at age 34. Which of the following conditions is this man most likely to have?

In a clinical study of patients with diabetes mellitus, a group of patients is found who had blood glucose measurements ranging from 140 to 180 mg/dL for at least 10 years. Rectal biopsies from these patients now show that there is a form of osmotic cellular injury present in arterioles. This form of injury is most likely to be manifested by which of the following complications?

A 49-year-old woman has experienced marked pain in her lower extremities on ambulation more than 300 meters for the past 5 months. On physical examination, her lower extremities are cool and pale, without swelling or erythema. No dorsalis pedis or posterior tibial pulses are palpable. Her body mass index is 32. She is a smoker. Which of the following abnormalities of the vasculature is most likely to account for these findings?

An autopsy study is conducted involving the gross appearance of the aorta of adults ranging in age from 60 to 90. In some of these patients, the aorta demonstrates atheromatous plaques covering from 70 to 95% of the intimal surface area, mainly in the abdominal portion, with ulceration and calcification. Which of the following contributing causes of death are these patients most likely to have?

A 59-year-old woman has the sudden onset of severe dyspnea and goes into cardiac arrest, from which she cannot be resuscitated. At autopsy, she has the gross finding of a saddle pulmonary embolus. This event is most likely to be present as a consequence of which of the following?

At autopsy, the kidneys of a 44-year-old woman who died suddenly are found to be of normal size. Their surfaces appear finely granular. There are small hemorrhages noted. The cortices appear pale. Microscopically, many small renal arteries and arterioles demonstrate concentric intimal thickening with marked luminal narrowing. These findings are most likely to be present as a result of which of the following underlying diseases?

A 35-year-old previously healthy woman notes that she has bruises form on her arms and legs with just minor trauma. Physical examination reveals areas of purpura from 1 to 3 cm in size over her trunk and extremities, but no swelling, warmth, or erythema. Peripheral pulses are all palpable and full. Her blood pressure is 110/70 mm Hg. An ultrasound examination of her lower extremities with Doppler flow measurement reveals no evidence for thrombosis. Laboratory findings include serum urea nitrogen of 20 mg/dL, LDH 300 U/L, total protein 6.9 g/dL, albumin 5.3 g/dL, alkaline phosphatase 50 U/L, AST 40 U/L, and ALT 20 U/L. Which of the following additional laboratory findings is most likely to be present in this patient?

Grandma falls down the steps leading to the entrance of the house of a relative hosting a family reunion, who is heard to remark, "I've been meaning to get that loose step fixed." Grandma is hospitalized for surgery to replace the broken hip she sustains and is then moved to a nursing home, but she is unable to ambulate until about a month later, when she dies suddenly. Which of the following is most likely to be the immediate cause of death found at autopsy?

A 53-year-old woman is found on a routine physical examination to have vital signs with T 36.9 C, P 77/minute, R 15/minute, and BP 165/110 mm Hg. There are no other significant findings. She has an abdominal ultrasound examination that shows the right kidney to be atrophic. Angiography reveals markedly reduced blood flow to the right renal artery from an occlusion at the orifice in the abdominal aorta. Which of the following laboratory findings is she most likely to have?

A study of pathologic findings in the islets of Langerhans is performed. It is observed that insulitis may occur in the islets. The inflammatory infiltrate is predominantly composed of T lymphocytes. Which of the following is most likely to occur as a consequence of insulitis?

A 20-year-old man incurs blunt trauma to his upper outer arm. On physical examination, there is a 2 x 3 cm contusion. The initial soft tissue bleeding stops in a few minutes and the size of the bruise does not increase. Which of the following chemical mediators is most important in this episode of hemostasis?

A 45-year-old man feels some crushing chest pain along with numbness in his left arm after shoveling 15 cm of snow off his driveway. Three hours later he collapses and is taken to the emergency room. Which of the following laboratory tests run on a blood specimen is most useful in this situation?

A 68-year-old woman has survived multiple episodes of pulmonary thromboembolism during the past three months. Which of the following is the most likely underlying condition leading to this patient's recurrent pulmonary thromboembolism?

A 77-year-old woman has experienced abdominal pain for the past month. On physical examination, she has a pulsatile lower abdominal mass. An abdominal CT scan reveals an abdominal aorta dilated to 7 cm in diameter, with calcification of the aortic wall. While awaiting surgery, she has an episode of severe abdominal pain and a repeat CT scan shows marked retroperitoneal hemorrhage. Which of the following laboratory test findings is she most likely to have?

A 70-year-old man has noted coldness and numbness of his lower left leg, increasing over the past 4 months. He also experiences pain in this extremity when he tries walking more than the distance of half a city block. On physical examination, his dorsalis pedis, posterior tibial, and popliteal artery pulses are not palpable. Which of the following laboratory test findings is he most likely to have?

A 72-year-old man suffered a myocardial infarction involving half the left ventricular free wall 3 months ago. He now has increasing dyspnea and orthopnea. On echocardiography his ejection fraction is 29%. On examination he has poor capillary filling in hands and feet. A chest x-ray shows pulmonary edema. Which of the following laboratory test analytes is most likely to be increased in this man at this point in time?

A 44-year-old African-American man has had elevated blood pressure for years which has not been treated. He now has severe headaches. On physical examination his blood pressure is 275/150 mm Hg. Laboratory studies show Hgb 13.8 g/dL, serum glucose 76 mg/dL, and creatinine 3.5 mg/dL. These findings are most likely to be associated with which of the following pathologic lesions involving his kidneys?

A 60-year-old woman has become increasingly obtunded over the past day. She was found by her daughter in a stuporous condition and brought to the emergency department. On physical examination, she has poor skin turgor. She is afebrile. Her vital signs reveal a blood pressure of 90/40 mm Hg, respirations 15 and shallow, pulse 95, and temperature 36 C. Laboratory studies show a hemoglobin A1C of 10%. Her serum electrolytes show sodium 144 mmol/L, potassium 5 mmol/L, chloride 95 mmol/L, CO2 22 mmol/L, and glucose 940 mg/dL. Which of the following is the most likely diagnosis?

A study is performed involving persons who have a history of diabetes mellitus type 1 or type 2. These patients are found to have cellular injury that results from glycosylation end products and from sorbitol accumulation within cells. The same patients are also shown to have ischemic tissue damage from accelerated and advanced atherosclerosis. Which of the following complications is most likely to result from atherosclerosis in these patients?

A 30-year-old man goes to his physician for a routine health checkup. On physical examination there are no abnormal findings. Laboratory test findings include serum glucose 80 mg/dL, hemoglobin A1C 4%, total cholesterol 240 mg/dL, LDL cholesterol 180 mg/dL, and HDL cholesterol 20 mg/dL. Through which of the following mechanisms is endothelial vascular injury in this patient most likely to occur?

A 65-year-old man has had increasing lower leg swelling along with reduced exercise tolerance for the past 5 years. He sometimes has chest pain on exertion. He has not experienced dyspnea. He has experienced 4 episodes of transient ischemic attacks in the past year. He has experienced abdominal pain in the past 2 months. Vital signs show T 36.9 C, P 82/min, RR 15/min, and BP 130/85 mm Hg. He has pitting edema to the knees bilaterally. The lower extremities have palpable pulses, no tenderness, and no erythema. An abdominal CT scan shows dilation of the abdominal aorta to 5 cm, filled with mural thrombus. Other family members have had similar problems. Which of the following underlying conditions is most likely to produce these findings:

A 45-year-old woman who has been bedridden for several weeks has the onset of left sided chest pain along with dyspnea. She has some tenderness in her left leg, which has a slightly greater circumference in the thigh than the right. A ventilation/perfusion scan shows evidence for a left lower lobe perfusion defect. Which of the following vascular diseases is most likely to cause these findings:

A 27-year-old woman had a hemoglobin A1C of 7.9% noted during a prenatal visit. She gives birth to a 4350 gm baby at 37 weeks gestation. Just after the delivery, the baby becomes irritable and displays seizure activity. Which of the following laboratory findings is most likely to be found in the baby:

Which of the following chemical components of the blood is mainly responsible for transporting exogenous (dietary) triglyceride from the intestine following a meal.

Some cells demonstrate glucose uptake regardless of the plasma insulin level. In a person who has had persistent hyperglycemia for years, cellular injury can occur. Which of the following cell types is most likely to show injury from hyperglycemia:

During hospitalization, a 40-year-old woman develops thrombophlebitis. She recovers and is discharged. She returns to her job as an electrician. A couple of months later, which of the following terms would best describe the process seen in a femoral vein after recovery from her thrombophlebitis:

A 52-year-old man has an ulcerated area on the sole of his foot that has not healed for 2 months. He is 180 cm tall, weighs 126 kg, and has continued to gain weight gradually. He has not had any major illnesses. His blood pressure is normal. Which of the following laboratory tests performed on serum from a blood sample would be most useful in elucidating the underlying cause for his problem:

A 57-year-old man has had blood pressure measurements in the range of 160/95 to 180/110 mm Hg for many years. He has taken no medications. A renal scan reveals kidneys of normal size for age. These findings with benign nephrosclerosis are most likely to occur with which of the following vascular changes:

A 70-year-old woman with a history of type II diabetes mellitus is found comatose at her home. There are no external signs of trauma. When seen a week ago she was depressed, but in no apparent distress. She had not been ingesting much food or drinking much water for several days. Vital signs show T 35.8 C, P 85, R 16, and BP 100/65 mm Hg. Which of the following laboratory test findings is most likely to be present:

A 20-year-old woman was diagnosed last year with pulmonary thromboembolism. In her 6th month of her first pregnancy, she delivered a stillborn baby. Laboratory testing revealed the presence of a normal prothrombin time, normal partial thromboplastin time, platelet count of 250,000/microliter, and presence of lupus anticoagulant. These findings are most characteristic for which of the following hypercoagulable states:

A 52-year-old woman has a history of urinary tract infections. Recently, one of these episodes was complicated by acute pyelonephritis involving her kidneys. She became septic, and a blood culture grew Escherichia coli. She developed severe hypotension. She had purpuric areas on her skin. A stool for occult blood was positive. She had a prothrombin time of 50 sec (control 12), partial thromboplastin time of 100 sec (control 25), platelet count of 20,000/microliter, and D-dimer of 4 microgm/mL. These findings are most characteristic for which of the following conditions:

A 48-year-old woman has a malignant lymphoma involving lymph nodes in the para-aortic region. She is treated with a chemotherapeutic agent which results in the loss of individual neoplastic cells through fragmentation of individual cell nuclei and cytoplasm. Over the next 2 months, the lymphoma decreases in size, as documented on abdominal CT scans. By which of the following mechanisms has her neoplasm primarily responded to therapy?

A 53-year-old man has experienced severe chest pain for the past 6 hours. On physical examination he is afebrile, but has tachycardia. Laboratory studies show a serum troponin I of 10 ng/mL. A coronary angiogram is performed emergently and reveals >90% occlusion of the left anterior descending artery. In this setting, an irreversible injury to myocardial fibers will have occurred when which of the following cellular changes occurs?

While in a home improvement center warehouse buying paint, a 35-year-old man hears "Look out below!" and is then struck on the leg by a falling pallet rack, which strikes him on his left leg in the region of his thigh. The skin is not broken. Within 2 days there is a 5 x 7 cm purple color to the site of injury. Which of the following substances has most likely accumulated at the site of injury to produce a yellow-brown color at the site of injury 16 days later?

A54-year-old man with a chronic cough has a squamous cell carcinoma diagnosed in his right lung. While performing a pneumonectomy, the thoracic surgeon notes that the hilar lymph nodes are small, 0.5 to 1.0 cm in size, and jet black in color throughout. Which of the following is the most likely cause for this appearance to the hilar nodes?

A 50-year-old woman with a history of unstable angina suffers an acute myocardial infarction. Thrombolytic therapy with tissue plasminogen activator (tPA) is administered to restore coronary blood flow. In spite of this therapy, the degree of myocardial fiber injury may increase because of which of the following cellular abnormalities?

A 12-year-old boy has had multiple episodes of ear pain accompanied by fever. On examination his right tympanic membrane is red and bulging with yellow exudate. Laboratory studies of the exudate show culture positive for Hemophilus influenzae. A year later he has conductive hearing loss on the right, and a head CT scan shows a mass in the right middle ear. Which of the following materials is most likely to be seen in the tissue curetted from his middle ear?

A 43-year-old man has complained of mild burning substernal pain following meals for the past 3 years. Upper GI endoscopy is performed and biopsies are taken of an erythematous area of the lower esophageal mucosa 3 cm above the gastroesophageal junction. There is no mass lesion, no ulceration, and no hemorrhage noted. The biopsies show the presence of columnar epithelium with goblet cells. Which of the following mucosal alterations is most likely represented by these findings?

A 59-year-old woman had the loss of consciousness that persisted for over an hour. When she becomes arousable, she cannot speak nor move her right arm or leg. A cerebral angiogram revealed an occlusion to her left middle cerebral artery. Months later, a computed tomographic (CT) scan shows a large 5 cm cystic area in her left parietal lobe cortex. This CT finding is most likely the consequence of resolution from which of the following cellular events?

A 19-year-old woman gives birth to her first child. She begins breast feeding the infant. She continues breast feeding for almost a year with no difficulties and no complications. Which of the following cellular processes that began in the breast during pregnancy allowed her to nurse the infant for this period of time?

An 80-year-old man dies from complications of Alzheimer disease. At autopsy, his heart is small (250 gm) and dark brown on sectioning. Microscopically, there is light brown perinuclear pigment with H&E staining of the cardiac muscle fibers. Which of the following substances is most likely increased in the myocardial fibers to produce this appearance of his heart?

In an experiment, a series of immunohistochemical stains are employed to identify different cellular components. One particular stain identifies the presence of intermediate filaments within cells. This cytokeratin stain is most likely to be useful for which of the following diagnostic purposes?

A 20-year-old woman had Goodpasture syndrome which progressed to chronic renal failure. She was 165 cm tall and weighed 55 kg. She had blood pressure measurements in the range of 150/90 to 180/110 mm Hg, but she did not regularly take medications. Laboratory studies showed her blood urea nitrogen was over 100 mg/dL. She required chronic dialysis. She died from heart failure. At autopsy, her heart weighed 540 gm. The size of her heart is most likely to be the result of which of the following processes involving the myocardial fibers?

A 29-year-old man goes on a snorkeling trip to Looe Key Marine Sanctuary and later spends time on the beach at Bahia Honda State Park. The next day he has a darker complexion. His skin does not show warmth, erythema, or tenderness. His skin tone fades to its original appearance within a month. Which of the following substances contributes the most to the biochemical process leading to these skin changes?

A study is performed to identify predisposing risks for tissue changes. In some persons epithelial metaplasia occurs. In which of the following situations is the process of epithelial metaplasia most likely to take place?

In an experiment, a disease process is found which leads to scattered loss of individual cells, with the microscopic appearance of karyorrhexis and cell fragmentation. The overall tissue structure remains intact. This process is most typical for which of the following diseases?

A 60-year-old woman has noted a dark red-black appearance to her great toe and second and third toes of her left foot for the past month. On physical examination, the toes are cold to touch and have no sensation to touch. The dorsalis pedis and posterior tibial pulses are not palpable on the left. A transmetatarsal amputation is performed. These findings are most typical for a patient with which of the following conditions?

A study is performed involving the microscopic analysis of tissues obtained from surgical procedures. Some of these tissues have the microscopic appearance of an increased cell size of multiple cells within the tissue, due to an increase in the amount of cytoplasm, with nuclei remaining uniform in size. Which of the following conditions is most likely to have resulted in this finding?

A 17-year-old adolescent receives whole body radiation as part of a preparatory regimen for bone marrow transplantation to treat acute lymphocytic leukemia. Which of the following cells and tissues in the body is most likely to remain unaltered by the effects of this therapeutic radiation?

A 79-year-old man has a large myocardial infarction involving much of the left ventricular free wall. He develops congestive heart failure (CHF) with decreased cardiac output. Now, a year later, his CHF is worsening. By echocardiography there is a large, bulging akinetic area typical for a left ventricular aneurysm. Which of the following laboratory tests on serum would best indicate poor peripheral tissue perfusion in this patient?

A 22-year-old woman has a congenital anemia. She has required multiple transfusions of red blood cells for many years. She now has no significant findings on physical examination. Laboratory studies now show a serum AST of 74 U/L and ALT 75 U/L with albumin 3.6 g/dL. Which of the following microscopic findings would most likely appear in a liver biopsy?

A 20-year-old man is involved in a motor vehicle accident which results in multiple blunt trauma and lacerations to his lower extremities. The left femoral artery is lacerated, and he incurs extensive blood loss and remains hypotensive for hours during transport to the emergency department. On admission, his hematocrit is 12%. Which of the following tissues is most likely to withstand the impact of these events with the least damage?

A 40-year-old woman has the sudden onset of severe abdominal pain. On physical examination she has diffuse tenderness in all abdominal quadrants, with marked guarding and muscular rigidity. She has laboratory findings that include serum AST of 43 U/L, ALT of 30 U/L, LDH 630 U/L, and lipase 415 U/L. An abdominal CT scan reveals peritoneal fluid collections and decreased attenuation along with enlargement of the pancreas. Which of the following cellular changes is most likely to accompany these findings?

A 26-year-old man died from complications of destruction of the aortic valve by large, irregular vegetations from which Staphylococcus aureus was cultured. At autopsy, the spleen on sectioning grossly reveals the presence of a tan to white, wedge-shaped 1.5 x 3 cm lesion with base on the capsule. The splenic findings are most likely to result from which of the following cellular abnormalities?

A 35-year-old woman developed increasing icterus over the last week of life. Laboratory studies had shown hyperammonemia. She is found at autopsy to have a 3500 gm liver with a uniform, yellow, greasy cut surface. No necrosis of hepatocytes is noted microscopically. This pathologic appearance of the liver most likely resulted from which of the following conditions?

A clinical study is performed in which the conditions leading to the appearance of calcification on chest and abdominal CT scans are analyzed in patients from 60 to 90 years of age. One set of patients has the finding of incidental calcification, with no serious health problems. In which of the following tissue locations was this incidental calcification most likely to be noted?

A 55-year-old man has a 30-year history of poorly controlled diabetes mellitus. He has had extensive black discoloration of skin and soft tissue of his right foot, with areas of yellowish exudate, for the past 2 months. Staphylococcus aureus is cultured from this exudate. A below-the-knee amputation is performed. The amputation specimen received in the surgical pathology laboratory is most likely to demonstrate which of the following pathologic abnormalities?

The lifestyle patterns of healthy persons from 20 to 30 years of age are studied. A subset of these persons have a lifestyle characterized by consumption of a lot of pizza and very little physical exercise. Which of the following tissue changes is most likely to develop in this subset of persons as a consequence of this lifestyle?

In an experiment, a tissue preparation is subjected to oxidant stress. There are increased numbers of free radicals generated within the cells. Generation of which of the following substances within these cells is the most likely protective mechanism to reduce the number of free radicals?

A 38-year-old man incurs a traumatic blow to his upper left arm. He continues to have pain and tenderness even after 3 months have passed. A plain film radiograph reveals a 4 cm circumscribed mass in the soft tissue adjacent to the humerus. The mass contains areas of brightness on the x-ray. Over the next year this process gradually resolves. Which of the following terms best describes this process?

A 31-year-old primigravida has a difficult delivery of a term infant, with loss of 1500 cc of blood. She has hypotension for 6 hours. Over the next month, her ACTH level decreases. Within the next 3 months, her adrenal glands become only about 2 grams each (normal 4 to 6 grams). This alteration of the adrenals is primarily due to which of the following cellular processes?

A 48-year-old man has a history of chronic alcohol abuse. He is still able to perform work at his job. He has had no major illnesses. On physical examination, there are no significant findings. Laboratory studies show a serum albumin of 4.1 g/dL, ALT 40 U/L, AST 40 U/L, and total bilirubin 1.1 mg/dL. Which of the following microscopic findings in his liver is most likely to be present?

A 44-year-old woman has had episodes of right upper quadrant pain during the past 2 weeks. Her stools have become pale in color over the past 3 days. Laboratory studies show a serum total bilirubin of 9.7 mg/dL. A cholangiogram shows that a gallstone has passed into the common bile duct, resulting in obstruction of the biliary tract. Which of the following cellular alterations is most likely to be visualized on her skin surfaces?

A 45-year-old man has a traumatic injury to his forearm and incurs extensive blood loss. On physical examination in the emergency department his blood pressure is 70/30 mm Hg. Which of the following cellular changes is most likely to represent irreversible cellular injury as a result of this injury?

A 73-year-old man suffers a "stroke." On physical examination he cannot move his right arm. A cerebral angiogram demonstrates occlusion of the left middle cerebral artery. An echocardiogram reveals a thrombus within a dilated left atrium. Which of the following is the most likely pathologic alteration from this event that has occurred in his brain?

A 30-year-old woman is claiming in a civil lawsuit that her husband has abused her for the past year. A workup by her physician reveals a 2 cm left breast mass. There is no lymphadenopathy. No skin lesions are seen, other than a bruise to her upper arm. An excisional biopsy of the breast mass is performed. On microscopic examination, the biopsy shows fat necrosis. This biopsy result is most consistent with which of the following etiologies?

A 45-year-old man has smoked 2 packs of cigarettes per day for the past 30 years. He has had a chronic cough for the past 3 years, worsening over the past 2 weeks. A suspicious left pulmonary parenchymal lesion is seen on a chest x-ray. He has a bronchoscopy performed. A biopsy of a segmental bronchus shows squamous metaplasia. Which of the following is the most appropriate interpretation of this finding?

A 45-year-old woman has had congestive heart failure for the past 4 years. She develops a fever that persists for over a week. On physical examination, a heart murmur is present. Her temperature is 38.4 C. The spleen tip is palpable. On echocardiography she has an abnormally thickened mitral valve. Laboratory studies show a blood culture positive for Streptococcus, viridans group. Another echocardiogram reveals a 1 cm vegetation on the superior aspect of her mitral valve. Which of the following findings would you most expect to appear in the kidney as a consequence of these events?

A 19-year old G2 P1 woman has an amniocentesis performed at 18 weeks gestation. Fibroblasts recovered from amniocentesis are grown in culture to assess the karyotype of fetal cells. These cells are subcultured for additional experimental work, but the culture is lost after 50 doublings of the cells has occurred, and the fibroblasts no longer grow. Which of the following factors affecting these cells is most likely demonstrated by this phenomenon?

A 55-year-old man has sudden onset of severe, sharp chest pain with diaphoresis and dyspnea. On physical examination he has tachycardia with an irregular heart rhythm. Electrocardiographic changes suggest the possibility of focal myocardial damage involving the left lateral ventricular wall. Which of the following laboratory tests on the patient's serum is most useful in this situation?

A 42-year-old previously healthy woman notes that over the past week her eyes have developed a yellowish appearance. She has had mild nausea and vomiting over the past week. On physical examination she has scleral icterus. She has no other major physical examination findings except for mild right upper quadrant tenderness. Which of the following underlying conditions is most likely to contribute to development of her icterus?

A 56-year-old woman has smoked 2 packs of cigarettes per day for the past 35 years. She has had a chronic cough for the past 8 years, but recently has noted increased sputum production. On physical examination she has a few crackles auscultated best over the lung bases. Bronchoscopy with biopsy is performed. The biopsy reveals bronchial epithelium with squamous metaplasia. Which of the following statements represents the best interpretation of these findings?

A 90-year-old woman dies from pneumonia complicating Parkinson disease. At autopsy her heart is normal in size. On microscopic examination, there is increased lipochrome (lipofuscin) seen adjacent to the nuclei within the myocardial fibers. This microscopic finding is most likely to result from which of the following cellular mechanisms?

An experiment is conducted to determine if cell membrane injury is lessened by the effects of vitamin E ingestion. Which of the following cellular components is primarily involved in generation of lipid peroxides, the formation of which is inhibited by the vitamin E?

A 35-year-old woman has had headaches and abdominal pain worsening for 3 months. There are no remarkable physical examination findings. On radionucleide scanning of the neck, she is found to have a mass involving one of her parathyroid glands. An abdominal CT scan suggests extensive nephrocalcinosis along with urinary tract calculi. Which of the following laboratory test findings is most likely to accompany her disease?

A 21-year-old woman has a routine Pap smear performed for a health screening examination. The pathology report indicates that some cells are found cytologically to have larger, more irregular nuclei. A follow-up cervical biopsy microscopically demonstrates disordered maturation of the squamous epithelium, with hyperchromatic and pleomorphic nuclei extending nearly the full thickness of the epithelial surface. No inflammatory cells are present. Which of the following descriptive terms is best applied to these Pap smear and biopsy findings?

A 38-year-old man has a health screening examination. He has a routine chest x-ray that shows a 2 cm nodule in the right lower lobe. The nodule has focal calcifications. A wedge resection of the nodule is done. On microscopic examination the nodule shows caseous necrosis and calcification. Which of the following processes explains the appearance of the calcium deposition:

A 3-year-old child has been diagnosed with ornithine transcarbamylase deficiency and has developed hepatic failure. The left lobe of an adult donor liver is used as an orthotopic transplant. A year later, the size of each liver in donor and recipient is greater than at the time of transplantation. Which of the following cellular alterations is most likely to explain this phenomenon?

A morbidly obese 51-year-old woman dies from complications of heart disease. At autopsy, her heart weighs 600 gm (normal up to 300 gm) with all the chambers enlarged. Microscopically, there is increased fibrous connective tissue seen in the interstitium between myocardial fibers. The fibers are increased in size. Beneath the epicardium can be seen adipocytes interdigitating with the myocardial fibers. Which of the following terms best describes the presence of the adipocytes in her myocardium?

A 48-year-old man has an episode of severe substernal chest pain radiating to his left arm. Four months later he has increasing dyspnea and orthopnea. On physical examination there are rales heard over all lung fields. An echocardiogram shows a left ventricular aneurysm. He has decreased cardiac output with an ejection fraction of 29%. Which of the following findings is most likely to be indicative of the original acute event at the time he presented with chest pain?

A 53-year-old man suffers a cardiac arrest and his wife calls emergency services. The paramedics arrive a few minutes later and begin life support measures. A regular heart rate is established after about 40 minutes of resuscitative efforts as he is being transported to the hospital. A thrombolytic agent (tPA) is administered. Which of the following cellular processes is most likely to occur in his myocardium following administration of the tPA?

A 38-year-old woman has severe abdominal pain with hypotension and shock that has developed over the past 36 hours. On physical examination, her abdominal muscles are rigid and her abdomen is extremely tender. An abdominal CT scan reveals fluid density in the region of the pancreas, which appears to be enlarged. Which of the following laboratory test findings in her serum is most likely to be present?

A 45-year-old man has noted scleral icterus for the past 4 days. He has been feeling tired and "run down" for about a month. On physical examination, other than mild tachycardia, his vital signs are normal. No other physical examination findings are of noted other than scleral icterus. Laboratory studies show a hematocrit of 25%. Which of the following conditions is most likely to account for these findings?

A 49-year-old man with a history of alcohol abuse has increasing abdominal girth. On examination his liver edge is firm. A liver biopsy shows cirrhosis, and individual hepatocytes contain red, globular inclusions positive for cytokeratin with immunohistochemical staining. Which of the following structural elements are these intracellular globules most likely to contain?

A 30-year-old woman has been previously diagnosed with systemic lupus erythematosus. She has had chest pain for the past 6 months. A chest radiograph shows bilateral pleural effusions. Thoracentesis on the right yields 400 mL of clear yellow serous fluid, and a cell count shows only a few cells present. What type of cell is most likely to be most numerous in this fluid?

A newborn male infant is examined. There is a palpable right testis, but no left testis, in the scrotal sac. The infant has no other abnormalities noted. Which of the following is the most likely abnormality involving the gonads of this infant?

Following ovulation and fertilization of an ovum, a blastocyst develops. Growth and differentiation occurs following implantation. Which of the following will develop into the placenta?

A 5-year-old child fatigues easily. On examination a machinery-like murmur is auscultated over his chest. Echocardiography shows shunting of blood from the aorta to the pulmonary artery. An abnormality involving which of the following structures is most likely present in this boy?

A 3500 gm infant born at term is doing well and gaining weight normally until the fourth week of life. He then exhibits feeding difficulty with forceful vomiting. Now, on physical examination, no external anomalies are noted. However, there is a firm mass palpable in the upper mid abdominal region. Which of the following conditions is the infant most likely to have?

An infant born at term is examined, and there is abnormal fusion of the 3rd, 4th, and 5th digits of the left hand. A radiograph of the left hand shows transformation of metacarpals I, II, III, and V to short, carpal-like bones. A mutation involving which of the following genes most likely led to these findings?

An infant born at term has a radiograph taken. No congenital abnormalities are noted. The upper heart borders are not visualized. Which of the following structures is most likely to obscure the heart borders in this infant's radiograph?

A secondary oocyte is developing normally. At which of the following times does the second maturation division of meiosis become completed?

During the 3rd week of embryonic development, splanchnic mesoderm differentiates into blood islands with angioblasts. In what developing tissue site does this process occur?

An ovum is fertilized. After 3 weeks a blastocyst implanted on the endometrium has an inner embryoblast and an outer trophoblast. Which of the following is the next step in forming a 3-layered embryonic disk?

A 55-year-old man has noted sharp pain in his right lower extremity for the past 2 months. MR imaging of his spine shows impingement on a spinal nerve root by a herniated structure located between L5 and S1. From which of the following embryonic derivatives does this herniated structure most likely arise?

In the developing embryo, pharyngeal arches are formed. The second (branchial) arch gives rise to the stapedius, orbicularis oris, and posterior belly of the digastric muscles. Which of the following cranial nerves is also derived from this arch?

An infant born at 30 weeks gestation develops respiratory distress soon after birth. the infant is intubated and upon mechanical ventilation there are breath sounds auscultated over the right chest, but not over the left. An abnormality involving a derivative from which of the following embryonic structures is most likely present in this infant?

In the normally developing embryo, aortic arches are apparent by the end of the fourth week. Which of the following arteries is derived from the third pair of aortic arches?

A 19-year-old primigravida gives birth at term following an uncomplicated pregnancy to a 3000 gm male infant. He has not passed any stool by day 2 of life. On physical examination his abdomen is distended. An ultrasound scan shows a dilated colon. Laboratory studies show a normal sweat chloride test. A mutation involving which of the following genes is most likely to be present in this infant?

A fetus at 18 weeks gestation is normally formed and appropriately sized. No fetal or placental anomalies are present. Which of the following parts of the fetal vasculature is most likely to have the greatest oxygen concentration?

An embryonic eye is developing normally. A retina is present on the posterior aspect of the globe. What is the embryologic origin of the portion of retina containing nerve cell bodies?

A newborn examination is performed. The tympanic membranes are visualized bilaterally. What is the embryologic origin of the structure that forms the canal connecting the external ear to the tympanic membrane?

A 2-year-old child has difficulty eating and drinking. On examination, there is a lateral cleft that involves the right upper lip. This defect is most likely due to failure in development and fusion of which of the following?

A 20-year-old woman is unable to conceive and undergoes an infertility workup. A pelvic ultrasound reveals a bicornuate uterus. Which of the following is the most likely explanation for her anomalous uterus?

A newborn boy is noted to be dribbling urine. On examination he has a urethral opening on the ventral-midpoint of his penis. Abnormal development of which of the following structures is most likely responsible for his urinary problem?

In a developing embryo, neural crest cells form adjacent to the neural tube. These neural crest cells then undergo migration. Which of the following structures is derived from these migrating cells?

A newborn infant boy is noted to have an abnormality involving his perineum and scrotum. There is failure of midline fusion in the urogenital region. Chromosome analysis shows his karyotype is 46, XY. Which of the following is most likely responsible for his condition?

A neonate undergoes a check of health status. On examination a faint cardiac murmur is auscultated. Echocardiography is performed and shunting of blood is noted from the left atrium to the right atrium. An abnormality in embryonic development of which of the following structures has most likely occurred in this neonate?

The two superior and two inferior parathyroid glands are found adjacent to the posterior aspect of the thyroid gland. From which of the following are these parathyroid glands derived in embryologic development?

A 29-year-old woman describes mild discomfort with sexual intercourse for the past month. A pelvic examination reveals no vaginal discharge, and the cervix appears normal. On examination she has a small, slightly tender 2 cm mass in the lateral wall of her vagina. The excised mass is cystic, fluid filled, and lined by a cuboidal epithelium. This mass is most likely to be a remnant of which embryologic structure?

An infant is noted to have respiratory distress soon after birth. Physical examination reveals no external anomalies. A chest radiograph shows a left lung mass. A CT scan shows a peripheral, posterior left lower lobe lung posteriorly, with both cystic and solid components. Thoracic surgery is performed and the left lower lobe is removed without difficulty. There are no adhesions or abnormal vascular connections. Which of the following conditions is most likely to produce these findings?

A 31-year-old woman has noted no fetal movement by 16 weeks gestation. A fetal ultrasound shows the fetal head contains a brain with thin cortex, single enlarged ventricle, and fused thalami. Which of the following developing regions of the brain is most likely abnormal in this fetus?

During normal embryonic development, anterior-posterior differentiation occurs. By the end of the fifth week, dorsomedial somitic cells give rise to myotomes forming the epimere. Which of the following muscles is most likely derived from these cells?

In a study of vital statistics for the U.S., the causes for non-natural deaths are enumerated. Which of the following causes is most likely to account for the most deaths per year in the U.S.?

A 17-year-old driver was involved in a motor vehicle accident. He was thrown from the vehicle and sustained extensive blunt trauma with multiple fractures of the left tibia and fibula, left femur, and right humerus. He was in stable condition until three days after admission, when he suddenly became comatose and died. Autopsy is most likely to reveal which of the following gross pathologic findings?

A 20-year-old man is combative when police arrive at a house from which the neighbors heard screaming and breaking of glass for the past hour. He suddenly collapses. He is taken to the hospital, requiring resuscitation with defibrillation en route to try and establish a normal cardiac rhythm. On physical examination his vital signs show temperature 40 C, respirations 36/minute, heart rate 110/minute, and blood pressure 175/90 mm Hg. His pupils are dilated. He dies within an hour. Autopsy reveals no signs of major trauma. Which of the following drugs of abuse is most likely to produce these findings?

A 70-year-old man with a medical history of coronary atherosclerosis and congestive heart failure is beaten about the head and robbed. He is unconscious when admitted to the hospital. During his hospital course over the next two weeks he develops bronchopneumonia, sepsis and renal failure. He dies four days later. Which of the following conditions is the most likely underlying cause of death for this man?

A 30-year-old woman has been the victim of physical abuse by her spouse on multiple occasions, including punching her in the face and abdomen. After the most recent incident, she claims that he attacked her with a knife. Which of the following types of injuries are you most likely to find on physical examination of this woman which suggests that her spouse attacked her with a knife?

On a trip to the Caribbean, a 29-year-old man takes a scuba diving course. He goes on a wreck dive to a depth of 50 meters (170 feet). His diving partner signals to him that it is time to ascend, but he continues to explore the wreck, noticing some time later than he is running low on air. He panics and ascends to the surface quickly. Within 2 hours he then develops a headache, tightness in his chest, and difficulty breathing. He experiences generalized pain in all extremities. Which of the following injuries is the most likely cause for his findings?

A medical resident puts down the immediate cause of death as "Prematurity" followed by the underlying cause of death as "Hyaline membrane disease" on a death certificate form. Which of the following statements regarding this death certificate is most appropriate?

A 66-year old man has an episode of hemoptysis and comes to his physician. A chest x-ray shows a 5 cm mass in the left lung. Fine needle aspiration is performed and cells from the mass are examined microscopically, revealing a non-small cell carcinoma. The man is a non-smoker. Environmental exposure to which of the following agents is most likely to be a risk factor for development of this man's lung cancer?

A 20-year-old man was trapped inside a burning house and suffered 20% total body surface area (TBSA) burns to his arms. Though initially stable, he died 3 weeks later. Which of the following reasons most likely explains his death?

A 9-year-old girl is brought to the emergency department by her aunt. On physical examination there are multiple contusions of varying ages on the head, torso, arms, and thighs. A chest radiograph reveals a healing 6th rib fracture on the left. Her weight is slightly under that expected for age. The child appears listless. Which of the following conditions is the most likely diagnosis?

A 68-year-old woman is having minor elective eye surgery performed at a free-standing surgi-center. About 5 to 10 patients undergo various procedures each morning. She is next in line for surgery and has just been given pre-operative medications. Five minutes later, the nurse comes into the room where she is lying and discovers that she is not breathing. A crash cart and defibrillator for advanced cardiac life support are not available, so the nurse and doctor use mouth-to-mouth resuscitation and external chest compressions, but to no avail. At autopsy, the patient is found to have about 30% coronary atherosclerosis with 20% narrowing, a 300 gm heart, mild pulmonary emphysema, and minimal hepatic steatosis. A toxicology screen is negative for drugs of abuse and yields only traces of the medications used prior to surgery. Which of the following statements regarding this death is most accurate?

A 70-year-old man died suddenly and unexpectedly within 6 hours of admission to the hospital for a high fever that has been present for only 4 hours. At autopsy, there are no significant external findings on examination of the body. However, on opening the cranial cavity, the external surface of the markedly edematous brain shows an extensive yellow-tan exudate obscuring the sulci. Which of the following statements on this man's death certificate is most appropriate?

A 50-year-old man has had increasing dyspnea for 12 years, but no chronic cough. On physical examination he is afebrile. A chest radiograph reveals diffuse interstitial fibrosis involving both lungs. These findings are most likely produced by which of the following environmental exposures?

Therapeutic gamma irradiation is given to a 55-year-old woman for treatment of a breast carcinoma. The treatments occur over 6 weeks. The neoplasm diminishes in size during this time. Which of the following mechanisms of cellular injury is most likely to account for the efficacy of this radiation therapy?

A single, round, 9 mm penetrating wound on the forehead extends into the cranial cavity of a 31-year-old man examined at autopsy by the medical examiner. On the skin surface surrounding this wound is a 6 cm diameter area with grey-black stippling. Which of the following mechanisms of injury is most likely to produce these findings?

A 72-year-old woman was found dead in the bathtub in her home. She had been visited by her daughter 4 hours earlier and she appeared to be in good health. At autopsy, her brain grossly shows subarachnoid hemorrhage along with bilateral contusions inferiorly on frontal lobes. Which of the following accidental injuries is most likely to be the underlying cause of death?

A 46-year-old man has had increased sputum production and a chronic cough for the past 5 months. On physical examination there are expiratory wheezes heard over the right lung anteriorly. A chest x-ray demonstrates a 6 cm right perihilar mass. Laboratory studies include a sputum cytology, with the report that "Atypical cells are present suggestive of squamous cell carcinoma." Which of the following is most likely to be associated with these findings?

A couple returns home from a social event to find that their infant son is dead. The babysitter who was caring for the infant stated that she called emergency medical technicians after she checked on the infant and found him not breathing, and they could not revive the baby. The babysitter states that the child had been well an hour prior to this event. Which of the following findings in the body of the deceased infant documented by the medical examiner would most strongly suggest a non-natural mode of death?

A study is performed using autopsy findings from medical examiner cases of persons who were homeless and who were injection drug users. Toxicologic data is analyzed from these cases. For those persons who were found to have detectable opiates (as heroin) in liver tissue, which of the following conditions is the most likely immediate cause of death?

A 67-year-old man with a 60 pack year history of smoking was diagnosed with glioblastoma (high grade glioma) last year. He was seen by his physician a week ago and was in stable condition. He died suddenly at home last night. The physician must certify the death of this patient. Which of the following statements on the death certificate would be most appropriate to make?

Police officers respond to reports that an unclothed young man is running through the back yards of homes in a suburban neighborhood, climbing over fences and hedges and thrashing through swimming pools. The officers spot him on top of a utility pole. Toxicologic analysis of the man's blood is most likely to show which of the following substances?

Multiple deaths result from a shooting in a classroom at a high school. One of the suspects was reportedly seen earlier in the same classroom on the day of the shooting. What finding on the victims by the medical examiner is most suggestive that the assailant was in the same room, close to the victims as they were shot?

The 16-year-old driver of a motor vehicle hit a fixed object at a speed of 60 km/hr in a vehicular accident and dies at the scene. This driver's automobile had no functioning airbag and she was not wearing any restraints. She incurs blunt trauma to the abdomen. Which of the following injuries is the most probable immediate serious consequence of this accident?

A 64-year-old woman falls down some stairs at work. She suffers a right hip fracture for which she is hospitalized. She undergoes surgery for placement of a hip prosthesis. She is recuperating from the surgery when she suddenly develops dyspnea and expires in only a few minutes despite resuscitative measures. Autopsy reveals a saddle pulmonary embolus. A 1 cm infiltrating ductal carcinoma is found in the right breast, but there are no metastases. Which of the following statements regarding death certification is most accurate in this patient?

A 25-year-old woman is brought to the emergency room in an obtunded condition. She is afebrile. Laboratory studies show a serum sodium of 140 mmol/L, potassium 3.8 mmol/L, chloride 106 mmol/L, CO2 25 mmol/L, glucose 58 mg/dL, creatinine 1.1 mg/dL, AST 2150 U/L, ALT 2876 U/L, lipase 33 U/L, and calcium 9.0 mg/dL. She dies a day later. The microscopic appearance of her liver at autopsy demonstrates extensive necrosis of hepatocytes. Ingestion of which of the following substances is the most likely cause for these findings?

A 26-year-old healthy man visiting Arches National Park in southern Utah leaves the campground heading for double "O" arch some 8 km distant in 40 degree Celsius heat, ignoring the warning sign about carrying plenty of water. He collapses and is brought back to the park headquarters. Which of the following findings on examination by the emergency medical services technician is most likely to suggest that he has a condition unrelated to the hike?

A 31-year-old man is working on the ungrounded electrical wiring in his house. He has not flipped the switch on the circuit breaker. He accidentally touches the bare black wire of a 110 volt 20 ampere circuit. Which of the following is most likely to be the major life-threatening problem associated with this event?

A saddle-bronc rider in a rodeo was first crushed into the gate, then thrown from the horse, then stepped on and kicked by the horse, then dropped from the stretcher by the paramedics carrying him out of the arena. He sustained right femoral and left humeral fractures. Two days later he developed respiratory difficulty. Which of the following is the most likely immediate cause for his death?

A 13-year-old girl is playing soccer and runs into the post at the goal mouth, striking her left thigh. The coach runs out to determine the extent of the injury and he notes that there is intact skin with no bleeding at the site of injury. There is initially some swelling, and by the end of the day a red-purple color is present beneath the skin. Which of the following terms best describes her leg injury?

An 11-month-old infant is left unattended in a motor vehicle for 2 hours in an unshaded parking lot in summer with the doors shut and the windows of the vehicle rolled up. This infant is at greatest risk for the development of which of the following complications?

A 74-year-old man has been under the care of his physician for 9 years. He suffered an acute myocardial infarction 2 years ago and has since had poor exercise tolerance. His only abnormal laboratory test finding is a fasting blood glucose of 162 mg/dl two weeks ago. In the past his fasting blood glucose has ranged from 140 to 180 mg/dL. The physician is called one evening by his wife, who states that he is being taken to the emergency room, but he dies before the physician arrives. Which of the following statements is most appropriate regarding death certification in this case?

On a cool Fall day, April 29, 1996, a man walked into the Arrow Cafe in Port Arthur and began shooting with a .223 caliber semiautomatic rifle at all persons in and around the cafe. Many victims were shot as they were running away to exit the building. The assailant continued to fire at passers-by from the building and from stolen automobiles. In the late afternoon, when he was finally apprehended, 35 people were dead. Which of the following types of wounds did the medical examiner find on most of the victims:

A 55-year-old man has a history of diabetes mellitus, type II. He has the sudden onset of severe chest pain and is admitted to the hospital. Vital signs reveal temperature 36.9 C, pulse 88/minute, respirations 23/minute, and blood pressure 155/110 mm Hg. A chest radiograph reveals widening of the mediastinum. An angiogram reveals a tear of the proximal aorta. He is taken to surgery, and a hemopericardium is evacuated, but then he dies during the operative procedure. Which of the following is the most appropriate as the immediate cause of death given on the death certificate of this man?

A group of neo-nazis sets fire to the house of an immigrant family. Firemen find the bodies of three children trapped inside. Though the coroner cannot find burn injuries to the skin of the children, he is able to prove that the deaths were due to the fire by finding which of the following?

The body of a 17-year-old adolescent male is found near a dumpster behind the high school he attends. External examination reveals a single 9 mm circular wound on the right temple, with small surrounding lacerations and an abrasion ring. Sooting is found on his right hand. Autopsy reveals that he has widespread malignant lymphoma. The bullet is recovered beneath the scalp on the left side of his head. Which manner of death is most likely for this situation?

The body of a 13-year-old girl is found in her bed at home by Sheriff's deputies, who were called to the scene by a neighbor after he heard screaming sounds. Physical examination of the body reveals no external signs of trauma and no other abnormalities. A complete autopsy reveals no internal trauma or other abnormalities. Which of the following mechanisms of injury best explains these findings?

A study is performed analyzing patterns of injury. One type of injury, typically made with a blunt object, can be seen on physical examination and can be dated by the color change that takes place over time. Which of the following terms is most likely to describe this injury?

A 20-year-old man has joined a group of hikers ascending a mountain peak 8000 meters in height. Beginning at the 5000 meter level, he develops a worsening headache and increasing respiratory distress. He decides to press on. He spends a sleepless night while camped at 6000 meters. The next day, he becomes disoriented and cannot stay on the trail. While being attended by other members of the climbing party, he suddenly loses consciousness and cannot be resuscitated. Which of the following pathologic changes is most likely to be present in this man?

A child ingests 50 tablets in a bottle that she found on a table in the house. Two hours later, the child becomes progressively obtunded and then lapses into a coma. The child is taken to a local hospital, where supportive care is given. The child exhibits tachypnea and tachycardia, but is afebrile. Laboratory studies with blood gas analysis show metabolic acidosis. Which of the following substances did this child most likely ingest?

A 74-year-old man suffers extensive thermal burn injuries in a natural gas explosion and fire while lighting the furnace in the basement of his house. He has 40% total body surface area burns. Which of the following factors is most likely to determine whether skin grafting will be required?

The "employee of the year" is rewarded with a close-in parking space, but this space is very icy in winter, and she falls getting out of her car. She scrapes her arm on the pavement. She goes to the employee clinic, where the physician's assistant observes only a superficial epidermal injury in which the skin is not completely broken. Which of the following terms is most appropriate for the arm injury to this woman?

While driving a Williams-Renault formula one grand prix racing car in pursuit of the world driving championship at a race run in Italy, the Brazilian driver Ayrton Senna loses control and crashes. He dies moments later. The mode (manner) of death in this case is:

In an Agatha Christie mystery, the plot centers around a homicide that is made to look like a suicide. Though the famous Belgian detective Hercule Poirot eventually solves this mystery, the mode of death should have been obvious by inspection of the deceased's body, because he was alleged to have put the gun to his head and fired. Which of the following clue(s) is most likely to suggest homicide as the manner of death?

What type of object would you expect to have been found at the scene of the death of a woman with the following description of a wound by the medical examiner: "The incised wound of the neck is gaping and exposes the larynx and cervical vertebral column. It measures 5 1/2 inches in length and is found at the level of the superior border of the larynx":

Which of the following cases should be referred to the medical examiner to investigate and certify the death?

A 95-year-old woman falls to the ground after tripping on the carpet in her house. She strikes the back of her head on the floor. She becomes more irritable, with headache and decreasing mentation over the next 3 weeks. Which of the following complications of her injury is she most likely to have developed?

Which of the following items listed as the immediate cause of death on a death certificate is NOT acceptable?

A baby is born at term and is of normal birth weight, with Apgar scores of 9 and 10 at 1 and 5 minutes. Baby and mother are sent home on the second day following delivery. The baby does fine and is gaining weight and developing normally and is 4 months old. However, one night the mother checks on the baby and finds the infant prone on the bed and not breathing. Paramedics are called, but the infant cannot be resuscitated. Which of the following is the most probable explanation for these findings?

A 19-year-old man is taken to the emergency room after his mother finds him comatose on the floor of his room at home following a night of partying with his friends at a local club. Pertinent laboratory findings from a blood specimen taken postmortem include ALT of 830 U/L and AST of 1053 U/L, along with a significant amount of acetaminophen. Which of the following pre-existing conditions in the deceased is most likely to have contributed to this injury pattern?

A 66-year-old man dies suddenly and unexpectedly. He is found in his home by a neighbor after the man was not seen for over a day. Police find no evidence of foul play. At autopsy, there are no signs of physical injury. The skin of his hands displays cherry red lividity. Which of the following toxins is most likely to be found in this man?

An elderly man is found dead in his bed at home after paramedics are called by his neighbor, who noticed that the man was out working in his garden as he usually did, but collapsed. When paramedics arrive, the man is noted to have marked salivation with lacrimation. His pupils are pinpoint. He is incontinent of urine. On the way to the hospital he vomits. Which of the following environmental exposures best explains these findings?

A 27-year-old G2P1 woman is in the 39th week of gestation. A screening ultrasound at 19 weeks revealed no abnormalities. She goes into labor and 6 hours later has a routine vaginal delivery of a term male. An intact placenta is delivered 5 minutes later. The infant's Apgar scores are 8 and 9 and 1 and 5 minutes. However, within 10 minutes following delivery, she develops severe dyspnea and cyanosis, followed by seizures and coma. Which of the following is the most likely explanation for this series of events?

A bomb strikes the embassy of the People's Republic of China one evening in Belgrade. Several persons are killed immediately. By which of the following mechanisms did the victims most likely die from this event?

A 26-year-old woman is brought to the emergency room of a local hospital by her neighbor. She has 3 to 4 cm long linear incised wounds to the palms of the hands and to the ventral aspect of her wrists. Which of the following explanations offered by the woman for the appearance of these injuries are you most likely to believe?

A 3-month-old infant is found dead by his mother late one evening. She had put him in bed on his stomach only an hour before, and he had shown no signs of distress. The baby had been doing well prior to that time, feeding well and gaining weight normally. The baby's term birth had followed an uncomplicated pregnancy. Which of the following is the medical examiner most likely to find at autopsy of this infant?

A 79-year-old woman is found unconscious in the bedroom by firemen who respond to a report of a house fire by her neighbor. She is taken to a local hospital. She is found to have partial thickness burns involving her head and neck and full thickness burns involving most of her torso and upper extremities. Bronchoscopy reveals no erythema or ulceration of the trachea mucosa. Which of the following features described here suggests the best prognosis?

A 4-year-old previously healthy child ingests a 100 ml bottle containing a clear liquid he found under the kitchen sink at home. The child is observed to develop central nervous system depression over the next 6 hours. Acidosis is documented on admission to the hospital. Three weeks later, it is noted that the child's visual acuity is markedly decreased. Which of the following chemical substances was most likely present in the liquid ingested by this child?

A 15-year-old healthy girl with no major medical problems notes blotchy areas of erythema that are pruritic over the skin of her arms, legs, and trunk within an hour every time she eats seafood, followed by diarrhea. These problems abate within 3 hours, and then physical examination reveals no abnormal findings. Which of the following immunologic abnormalities is she most likely to have?

A 55-year-old man has developed progressive renal failure for the past 5 years. Microscopic examination of a renal biopsy shows extensive glomerular and vascular deposition of pink amorphous material on H&E staining. This material demonstrates apple-green birefringence under polarized light after Congo red staining. Immunohistochemical staining of these deposits is positive for lambda light chains. Which of the following conditions is most likely to be present in this man?

A 22-year-old woman has experienced episodes of myalgias, chest pain, and arthralgias for the past 3 years. On examination a friction rub is audible on chest auscultation and there is dullness to percussion at posterior lung bases. No joint deformity is noted. She has continued working at her job. She has a mild normocytic anemia. A chest x-ray shows bilateral pleural effusions. Which of the following laboratory screening tests is most appropriate to begin the workup for her condition?

A male infant is born at term. No congenital anomalies are noted on examination. A year later he now has failure to thrive and has been getting one bacterial pneumonia after another with both Hemophilus influenzae and Streptococcus pneumoniae cultured from his sputum. Which of the following diseases is he most likely to have?

A study is performed of outcomes involving patients who received renal allografts. It is noted that patients receiving allografts with matching to the donor by tissue typing for HLA-DR (Class II) antigens have a low rate of complications. Which of the following immunologic abnormalities is most likely to be diminished by tissue typing?

A 5-year-old boy has had recurrent pneumonia, meningoencephalitis, sinusitis, otitis and diarrhea since infancy. Bacterial and viral agents have been implicated, as well as Pneumocystis, Giardia, and Cryptosporidium. Laboratory studies show serum IgG 47 mg/dL, IgA 5 mg/dL, and IgM 671 mg/dL. Normal numbers of B and T cells are present. He is most likely to have a mutation involving a gene encoding for which of the following?

A 20-year-old woman has had symmetrical, proximal muscle weakness for 6 months. On exam she has 4/5 motor strength in all extremities. A deltoid biopsy shows a neutrophilic infiltrate with focal necrosis of the muscle fibers. Her antinuclear antibody test is negative, but she has histidyl-tRNA synthetase (Jo-1) antibody in her serum. Which of the following additional findings would be most likely be present in this patient?

Type I hypersensitivity responses of the immune system are accompanied by eosinophilia. An appropriate, useful type I response would most likely be directed against which of the following?

A 54-year-old woman goes to her physician because she has noted that during the past month her fingers become pale and painful upon exposure to cold. On exam she has mild dyspnea, but no wheezing. Her blood pressure is 170/110 mm Hg. Her antinuclear antibody test is positive with a titer of 1:256 and a nucleolar pattern. Her serum urea nitrogen is 15 mg/dL with creatinine of 1.1 mg/dL. Which of the following autoimmune diseases is she most likely to have?

Twelve hours after going on a hike through dense foliage, a 40-year-old man notices a slightly raised and tender irregular reddish rash on one forearm that was not covered by clothing. This rash gradually increases in intensity for 2 days and then fades away after two weeks. Which of the following forms of immunologic hypersensitivity is most likely demonstrated in this patient?

A 30-year-old woman has experienced myalgias for the past 3 months. On physical examination she has 5/5 motor strength in all extremities. She has dullness to percussion at lung bases. A chest x-ray shows bilateral pleural effusions. Laboratory studies show a positive antinuclear antibody test at a titer of 1:1024. Her serum urea nitrogen is 30 mg/dL. A renal biopsy is performed and microscopic examination shows a granular pattern of immunofluorescence staining with antibody to complement component C1q. This pattern is most typically produced as a consequence of which of the following immunologic mechanisms?

The second pregnancy for a 23-year-old woman appears uncomplicated until ultrasound performed at 19 weeks shows hydrops fetalis. The fetal organ development is consistent for 19 weeks, and no congenital anomalies are noted. Her first pregnancy was uncomplicated and resulted in the birth of a normal girl at term. The current pregnancy ends with birth of a baby boy at 32 weeks gestation. On examination the baby has marked icterus. Laboratory studies show a hemoglobin of 7.5 g/dL, and neonatal exchange transfusion is performed. Which of the following immunologic mechanisms best explains this infant's findings?

A previously healthy 12-year-old girl develops a sore throat over the past 2 days. On physical examination she has marked pharyngeal erythema with overlying yellowish exudate. A throat culture grows group A beta-hemolytic Streptococcus. Her pharyngitis resolves, but 3 weeks later she develops chest pain along with fever and malaise. The girl describes aching of her knees, hips, shoulders, and elbows. Multiple subcutaneous skin nodules are noted on physical examination, and she exhibits slight shaking movements of her head and neck. Her antistreptolysin-O and anti-DNAse B titers are elevated. Her creatine kinase MB fraction is elevated. Her findings are most likely the result of which of the following immunologic mechanisms?

A 60-year-old woman has developed crippling arthritis over the past 20 years. On physical examination the arthritis primarily involves her hands and feet, with marked joint deformities characterized by ulnar deviation and swan-neck deformities of her fingers. She has an irregular heart rate. Laboratory studies show that her rheumatoid factor titer is markedly elevated, but her antinuclear antibody test is negative. A rectal biopsy shows submucosal deposition of pink amorphous material that stains positively with Congo red. Which of the following precursor proteins most likely gave rise to these deposits?

A 35-year-old man has experienced a malar skin rash, polyarthritis with swelling and warmth of his hands, and sensitization to cold for the past 6 months. On physical examination he has generalized lymphadenopathy and pale conjunctivae. Laboratory findings include a hemoglobin of 9.5 g/dL, total WBC count of 2100/microliter, total serum protein 8.8 g/dL, albumin 3.6 g/dL, creatinine 1.1 mg/dL, and creatine kinase of 468 U/L. His antinuclear antibody test is positive at 1:256. Which of the following additional serologic tests is most likely to determine his underlying disease process?

A 48-year-old man has had a chronic cough with fever for 2 months. On physical examination his temperature is 37.9 C. A chest radiograph reveals a diffuse bilateral reticulonodular pattern. A transbronchial biopsy is performed and microscopic examination shows focal areas of inflammation containing epithelioid macrophages, Langhans giant cells, and lymphocytes. These findings are most typical for which of the following immunologic responses?

A 9-year-old boy has a sore throat. A throat culture grows group A hemolytic streptococcus. He receives antibiotic therapy. However, 17 days later he develops dark-coloured urine. Laboratory studies show 3+ blood on urinalysis. A renal biopsy is performed. On immunofluorescence staining the biopsy shows granular deposition of IgG and complement around glomerular capillary loops. Which of the following immune hypersensitivity mechanisms is most likely responsible for this pattern of findings?

A 40-year-old woman has had increasing difficulty swallowing for over the past year. She also notes that it is more difficult to use the keyboard of her computer because she finds it hard to move her fingers, though the joints are not painful. She has lost the facial wrinkles that she was beginning to develop in middle age. A skin biopsy is performed and shows extensive dermal fibrosis but almost no inflammatory cell infiltrates. These findings are most typical for which of the following conditions?

A 27-year-old woman is given intravenous penicillin to treat infective endocarditis. Within minutes of starting this therapy, she begins to have severe difficulty breathing with respiratory stridor and tachypnea. She suddenly develops an erythematous skin rash over most of her body. Her symptoms are most likely to be produced by release of which of the following chemical mediators?

A 42-year-old man has lost 7 kg over the past two years. During that time he has had pain and swelling around the small joints of his hands and feet. He has had a series of upper respiratory tract infections, with organisms including Staphylococcus aureus, Streptococcus pneumoniae, and Pseudomonas aeruginosa cultured. He has a chronic diarrhea. A stool specimen is found to have Giardia lamblia cysts. Laboratory studies show a hemoglobin of 8.8 g/dL with a reticulocyte count of 3.2%. His serum urea nitrogen is 19 mg/dL with creatinine 1.0 mg/dL. His antinuclear antibody test is negative. Quantitative serum immunoglobulins show IgA 70 mg/dL, IgG 303 mg/dL, and IgM 64 mg/dL. By flow cytometry there are normal numbers of T cells and slightly reduced numbers of B cells. Which of the following conditions is most likely to be present in this man?

A 31-year-old woman has noted chest pain for the past week. On physical examination she has decreased breath sounds with dullness to percussion at lung bases. A chest radiograph shows modest bilateral pleural effusions. On chest CT scan, the pleural effusions, as well as a pericardial effusion, are seen. A thoracentesis on the left yields clear fluid with a low protein and cell count. She is found to have an anti-double stranded DNA titer of 1:512. If she is later found to have a serum urea nitrogen that is 55 mg/dL, it will most likely be the result of which of the following pathologic processes?

A 28-year-old woman undergoes allogeneic bone marrow transplantation for acute leukemia. Three weeks later, she has marrow engraftment and her hemoglobin and WBC count are returning to normal. However, she has the appearance of a fine, scaling skin rash over her trunk and upper extremities. These findings are most consistent with which of the following complications?

A 22-year-old woman is bothered by an erythematous rash involving her cheeks and nose every time she spends more than a few minutes outdoors on a sunny day. On physical examination between these episodes, there are no abnormal findings. A biopsy of the skin involved with the rash shows deposition of IgG along the basement membrane by immunofluorescence microscopy, but uninvolved skin does not demonstrate this IgG deposition. Her antinuclear antibody test is negative. She has no other complaints. Her renal function tests are normal. Which of the following is the most likely diagnosis?

A 37-year-old woman develops a malar rash when she spends several hours outside at a Kensington Oval cricket match. Ordinarily, she avoids being in the sun, but a friend provided free tickets to a West Indies test match. When she sees her physician, a urinalysis is performed that shows hematuria and proteinuria. A skin biopsy shows immunofluorescence positivity along the dermal-epidermal junction with antibody to C1q. Which of the following additional complications is she most likely to suffer as a consequence of her underlying disease?

An 11-month-old infant has had upper and lower respiratory tract infections almost continuously since the time of birth, with organisms including Pneumocystis jiroveci and Pseudomonas aeruginosa identified. The baby also has oropharyngeal candidiasis. The baby succumbs to a cytomegalovirus pneumonitis. At autopsy, the thymus is markedly hypoplastic, and lymph nodes throughout the body are small, with absent germinal centers on microscopic examination. Which of the following mechanisms is most likely to explain these findings?

Every springtime, a young healthy man is bothered by episodes of nasal congestion accompanied by sneezing and watery eyes. He has no cough. On physical examination he is afebrile. There is swelling of his nasal passageways, but no other findings. His condition improves with use of a combination of loratadine and pseudoephedrine. His problems are most likely produced by release of chemical mediators from which of the following cell types?

A 28-year-old woman has noted occasional dyspnea for the past 13 months. She has also noted a non-productive cough and mild fever. Her symptoms improve when she is on vacation. A chest radiograph reveals nodular infiltrates. A transbronchial lung biopsy reveals microscopic findings consistent with an extrinsic allergic alveolitis with interstitial infiltrates composed of lymphocytes along with a few neutrophils and eosinophils. Which of the following is most likely to explain her findings?

A 30-year-old man has the sudden onset of fever, cough, and dyspnea. He has lost about 10% of his normal body weight over the past 6 months, along with a chronic, watery diarrhea. A bronchoalveolar lavage is performed, and cysts of Pneumocystis jiroveci are seen in the fluid. He is treated with clotrimoxazole and recovers. He develops pain and decreased vision on the right, and funduscopic examination reveals a cytomegalovirus retinitis; this improves with ganciclovir therapy. He develops tan-yellow plaques on his tongue with Candida albicans. Which of the following laboratory test findings is most likely to be present in this man?

A 40-year-old woman complains of dry mouth and dry eyes that have become almost constantly irritating during the past 2 years, regardless of her fluid intake or the weather outside. However, her fingers do not turn blue or painful upon exposure to cold. She is found serologically to have autoantibodies to the nuclear antigen SS-A, along with a positive antinuclear antibody test. Which of the following is most likely to be the worst long term complication of her underlying disease?

A 3-year-old boy has had numerous bacterial infections, including respiratory infections with Hemophilus influenzae, Streptococcus pneumoniae, and Staphylococcus aureus since infancy. He develops a polyarthritis that clears with immunoglobulin therapy. A lymph node biopsy is performed, and microscopically the germinal centers of his nodes are rudimentary. During the 3rd decade of his life he develops systemic lupus erythematosus. He demonstrates skin test positivity to Candida antigen. Laboratory studies show that his serum IgG is 110 mg/dL. His total WBC count is 7650/microliter with differential count of 65 segs, 4 bands, 22 lymphs, and 9 monos. Which of the following immunologic disorders best explains these findings?

A bee sting is suffered by a 28-year-old man, and his wife searches frantically for the medical kit with the injectable epinephrine. Which of the following immunologic mechanisms are they trying to circumvent?

A 35-year-old man has decreasing mobility of his spine, and he becomes more "hunched over" during the past 5 years. He has hip pain bilaterally. On physical examination he has loss of lumbar lordosis and diminished range of motion at the hips. A radiograph of the pelvis shows ankylosis with sacroiliitis of the sacroiliac joints bilaterally. No other joints appear to be affected. His antinuclear antibody test is negative. He has no other significant medical problems. Which of the following laboratory test findings is most likely to be present in this man?

A 45-year-old man has been plagued by mild chronic diarrhea and increased numbers of minor respiratory tract infections for most of his life. Following a motor vehicle accident with multiple lacerations to the lower leg, he has a significant blood loss requiring transfusion of blood products. During the transfusion, he is noted to have an anaphylactic transfusion reaction. Which of the following diseases is he most likely to have?

A 55-year-old woman has had increasing difficulty with swallowing over the past year. On physical examination her blood pressure is 210/110 mm Hg. Laboratory testing reveals a positive antinuclear antibody test with a nucleolar pattern on immunofluorescence. Her serum complement levels are normal. Which of the following lesions is most likely to be seen in her kidneys with renal biopsy?

A positive tuberculin skin test, with a firm 15 mm diameter dark red firm area of induration on the forearm, appears 60 hours following injection of the purified protein derivative (PPD). This finding is most likely to be a consequence of which of the following types of hypersensitivity reaction?

A study of immunofluorescence patterns in skin biopsies is performed. One immunofluorescence pattern with antibody to IgG that shows a band of immunofluorescence at the dermal-epidermal junction. This pattern is most likely to be based upon which of the following pathologic mechanisms?

A 15-year-old boy underwent bone marrow transplantation for aplastic anemia, with marrow donated from a sibling, with a 5 out of 6 antigen match. He later developed a fine, scaling skin rash as well as a watery diarrhea. Which of the following laboratory test findings is most likely to accompany this patient's disease?

A 50-year-old man with end stage renal disease from long-standing diabetes mellitus receives a cadaveric renal transplant. A month later, he has increasing malaise. His urine output decreases. Laboratory studies show a rising serum urea nitrogen and creatinine. The allograft is biopsied and seen microscopically to be undergoing destruction by cells which are recognizing graft cells expressing class I HLA antigens. Which of the following cells is most likely to mediate this response?

Persons infected with HIV are shown to have a period of clinical latency of infection lasting years. During this time their risk for infection by opportunistic pathogens is not increased. However, a reservoir of virus remains within their lymphoid tissues. Which of the following cells is most important to maintain this reservoir of HIV?

A 21-year-old man with serum IgA of 22 mg/dL, IgG of 175 mg/dL, and IgM of 40 mg/dL has had a high fever with cough productive of yellowish sputum for the past two days. Auscultation of his chest reveals a few crackles in both lung bases. A chest radiograph shows bilateral patchy pulmonary infiltrates. Which of the following inflammatory cell types will most likely be seen in greatly increased numbers in his sputum specimen?

A 31-year-old man incurs an injury in an industrial accident, with a steel H-beam striking the right side of his face, crushing the zygomatic arch and damaging the globe of the right eye. He undergoes plastic repair of bone and soft tissues and an attempt is made to salvage the eye. A month later, he has decreased visual acuity in both eyes, with choroidal thickening seen on funduscopic examination. The right eye is enucleated and shows prominent CD4 lymphocyte and macrophage infiltration of the uvea. By which of the following immunologic mechanisms has this condition most likely developed?

A neonate born at term developed tetany soon after birth. On physical examination the infant has a heart murmur. Laboratory studies show a serum calcium of 6.3 mg/dL. Echocardiography reveals a membranous intraventricular septal defect. Within the next year, this infant has bouts of Pneumocystis jiroveci pneumonia, Aspergillus fumigatus pneumonia, and parainfluenza virus and herpes simplex virus upper respiratory infections. Which of the following abnormalities most likely explains the development of this infant's findings?

A 45-year-old woman has experienced progressive, increasing muscular weakness, particularly toward the end of the day, over the past 2 months. She does not have arthralgias or myalgias. On physical examination her motor strength goes from 5/5 to 4/5 with repetitive movement of extremities. A chest CT scan reveals an anterior mediastinal mass. Laboratory studies show that her antinuclear antibody test is negative. By which of the following immunologic mechanisms is her disease most likely produced?

A 45-year-old woman has noted episodes of pain with swelling and warmth of her hands and feet for the past 3 weeks. During these episodes, lasting hours to days, it is difficult for her to walk or to prepare meals. On physical examination she has painful 1 cm subcutaneous nodules on the extensor surfaces of her elbows. Over the next 6 years, her hands become deformed so that it is difficult to perform tasks as simple as opening a door or buttoning her blouse. Which of the following laboratory test findings is she most likely to have?

A 22-year-old man develops marked right lower quadrant abdominal pain over the past day. On physical examination there is rebound tenderness on palpation over the right lower quadrant. Laparoscopic surgery is performed, and the appendix is swollen, erythematous, and partly covered by a yellowish exudate. It is removed, and a microscopic section shows infiltration with numerous neutrophils. The pain experienced by this patient is predominantly the result of the formation of which of the following two chemical mediators?

A 40-year-old woman had bilateral silicone breast implants placed two years ago. Since that time, she has noted increased firmness with slight deformity of the breast on the left. The implants are removed, and there is evidence for leakage of the implant contents on the left. Which of the following cell types is most likely to be most characteristic of the inflammatory response in this situation?

A 40-year-old man incurs a burn injury to his hands and arms while working on a propane furnace. Over the next 3 weeks, the burned skin heals without the need for skin grafting. Which of the following is the most critical factor in determining whether the skin in the region of the burn will regenerate?

A 58-year-old woman has had a cough with fever for 3 days. A chest radiograph reveals infiltrates in the right lower lobe. A sputum culture grows Streptococcus pneumoniae. The clearance of these organisms from the lung parenchyma would be most effectively accomplished through generation of which of the following substances by the major inflammatory cell type responding to this infection?

A clinical study is performed of patients with pharyngeal infections. The most typical clinical course averages 3 days from the time of onset until the patient sees the physician. Most of these patients experience fever and chills. On physical examination, the most common findings include swelling, erythema, and pharyngeal purulent exudate. Which of the following types of inflammation did these patients most likely have?

A 56-year-old man has had increasing dyspnea for 6 years. He has no cough or fever. He had chronic exposure to inhalation of silica dust for many years in his job. A chest x-ray now shows increased interstitial markings and parenchymal 1 to 3 cm solid nodules. His pulmonary problems are most likely to be mediated through which of the following inflammatory processes?

A 20-year-old woman has premature labor with premature rupture of fetal membranes at 20 weeks gestation. Prior to that time, the pregnancy had been proceeding normally. A stillbirth occurs two days later. Microscopic examination of the normal-sized placenta reveals numerous neutrophils in the amnion and chorion, but no villitis. These events are most likely to be mediated by the effects from release of which of the following substances?

After two weeks in the hospital following a fall in which she incurred a fracture of her left femoral trochanter, a 76-year-old woman now has a left leg that is swollen, particularly her lower leg below the knee. She experiences pain on movement of this leg, and there is tenderness to palpation. Which of the following complications is most likely to occur next after these events?

A 40-year-old woman has had a chronic cough with fever and weight loss for the past month. A chest radiograph reveals multiple nodules from 1 to 4 cm in size, some of which demonstrate cavitation in the upper lobes. A sputum sample reveals the presence of acid fast bacilli. Which of the following cells is the most important in the development her lung lesions?

A 20-year-old man has experienced painful urination for 4 days following spring break. A urethritis is suspected, and Neisseria gonorrheae is cultured. Numerous neutrophils are present in a smear of the exudate from the penile urethra. These neutrophils undergo diapedesis to reach the organisms. Release of which of the following chemical mediators is most likely to drive neutrophil exudation?

An episode of marked chest pain lasting 4 hours brings a 51-year-old man to the emergency room. He is found to have an elevated serum creatine kinase. An angiogram reveals a complete blockage of the left circumflex artery 2 cm from its origin. Which of the following substances would you most expect to be elaborated around the region of tissue damage in the next 3 days as an initial response to increase myocardial function and promote healing?

A 90-year-old woman has developed a fever and cough over the past 2 days. Staphylococcus aureus is cultured from her sputum. She receives a course of antibiotic therapy. Two weeks later she no longer has a productive cough, but she still has a fever. A chest radiograph reveals a 3 cm rounded density in the right lower lobe whose liquefied contents form a central air-fluid level. There are no surrounding infiltrates. Which of the following is the best description for this outcome of her pneumonia?

A 35-year-old woman has been taking acetylsalicylic acid (aspirin) for arthritis for the past 4 years. Her joint pain is temporarily reduced via this therapy. However, radiographs of her knees reveals continuing joint destruction with loss of articular cartilage and joint space narrowing. This pain reduction is most likely to be the result of diminishing which of the following chemical mediators?

A small sliver of wood becomes embedded in the finger of a 25-year-old man. He does not remove it, and over the next 3 days the area around the sliver becomes red, swollen, and tender. Neutrophils migrate into the injured tissue. Expression of which of the following substances on endothelial cells is most instrumental in promoting this inflammatory reaction?

An inflammatory process that has continued for 3 months includes the transformation of tissue macrophages to epithelioid cells. There are also lymphocytes present. Over time, fibroblasts lay down collagen as the focus of inflammation heals. These events are most likely to occur as an inflammatory response to which of the following infectious agents?

A 37-year-old man has had nausea and vomiting for 5 weeks. He experienced an episode of hematemesis yesterday. On physical examination he has no abnormal findings. Upper GI endoscopy is performed, and there is a 1.5 cm diameter lesion in the gastric antrum with loss of the epithelial surface. These findings are most typical for which of the following pathologic processes?

A 17-year-old driver of a pickup truck is involved in a collision. He incurs blunt force abdominal trauma. In response to this injury, cells in tissues of the abdomen are stimulated to enter the G1 phase of the cell cycle from the G0 phase. Which of the following cell types is most likely to remain in G0 following this injury?

A 19-year-old woman is in the early second trimester at 16 weeks gestation with her first pregnancy. On a routine prenatal visit, the nurse cannot detect fetal heart tones and an ultrasound reveals no fetal cardiac activity or fetal movement. The mother has noted no recent illness or other factors to account for this fetal demise. She is given a pharmacologic agent to induce abortion. By which of the following mechanisms is this induction most likely to be accomplished?

A 45-year-old woman has had a chronic, non-productive cough for 3 months, along with intermittent fever. She has a chest radiograph that reveals multiple small parenchymal nodules along with hilar and cervical lymphadenopathy. A cervical lymph node biopsy is performed. Microscopic examination of the biopsy shows noncaseating granulomatous inflammation. Cultures for bacterial, fungal, and mycobacterial organisms are negative. Which of the following chemical mediators is most important in the development of her inflammatory response?

A 55-year-old man has a history of hypercholesterolemia with coronary artery disease and suffered a myocardial infarction 2 years ago. He now presents with crushing substernal chest pain. Which of the following laboratory tests is most useful in diagnosing the cause of his chest pain?

A 15-year-old girl has had episodes of sneezing with watery eyes and runny nose for the past 2 weeks. On physical examination she has red, swollen nasal mucosal surfaces. She has had similar episodes each Spring and Summer when the amount of ragweed pollen in the air is high. Her symptoms are most likely to be mediated by the release of which of the following chemical mediators?

A 45-year-old man has been working hard all day long carrying loads of bricks to build a wall. He takes a non-steroidal anti-inflammatory drug (ibuprofen). Which of the following processes is this drug most likely to diminish in his arms?

Within minutes following a bee sting, a 37-year-old man develops marked respiratory stridor with dyspnea and wheezing. He also develops swelling and erythema seen in his arms and legs. An injection of epinephrine helps to reverse these events and he recovers within minutes. Which of the following chemical mediators is most important in the pathogenesis of this man's condition?

A 72-year-old woman did not get a "flu" shot in the fall as recommended for older persons. In the wintertime, she became ill, as many people in her community did, with a respiratory illness that lasted for 3 weeks. During this illness, she had a fever with a non-productive cough, mild chest pain, myalgias, and headache. What was her chest radiograph most likely to have shown during this illness?

In an experiment, Enterobacter cloacae organisms are added to a solution containing leukocytes and blood plasma. Engulfment and phagocytosis of the microbes is observed to occur. Next a substance is added which enhances engulfment, and more bacteria are destroyed. Which of the following substances in the plasma is most likely to produce this effect?

A 43-year-old woman has had nausea with vomiting persisting for the past 5 weeks. On physical examination there are no abnormal findings. She undergoes an upper GI endoscopy and gastric biopsies are obtained. The microscopic appearance of these biopsies shows mucosal infiltration by lymphocytes, macrophages, and plasma cells. Which of the following most likely caused her findings?

In an experiment, lymphatic channels are observed in normal soft tissue preparations. Staphylococcus aureus organisms are innoculated into the tissues and the immunologic response observed over the next 24 hours. Which of the following functions is most likely to be served by these lymphatics to produce a specific immune response to these organisms?

In an experiment, surgical wound sites are observed following suturing. An ingrowth of new capillaries is observed to occur within the first week. A substance elaborated by macrophages is found at the wound site to stimulate this capillary proliferation. Which of the following substances is most likely to have this function?

A 55-year-old man with a history of ischemic heart disease has worsening congestive heart failure. He has noted increasing dyspnea and orthopnea for the past 2 months. On physical examination there is dullness to percussion at lung bases. A chest x-ray shows bilateral pleural effusions. A left thoracentesis is performed, and 500 mL of fluid is obtained. Which of the following characteristics of this fluid would most likely indicate that it is a transudate?

In a clinical study, patients undergoing laparoscopic cholecystectomy are followed to document the post-surgical wound healing process. The small incisions are closed with sutures. Over the 4 weeks following surgery, the wounds are observed to regain tensile strength and there is re-epithelialization. Of the following substances, which is most likely found to function intracellularly in cells involved in this wound healing process?

A 31-year-old woman has a laparotomy performed for removal of an ovarian cyst. She recovers uneventfully, with no complications. At the time of surgery, a 12 cm long midline abdominal incision was made. You advise this patient of the outcome of this healing process, and indicate that tensile strength in the surgical scar will increase so her normal activities can be resumed. Most of the tensile strength will likely be achieved in which of the following time periods?

A 9-year-old girl sustains a small 0.5 cm long laceration to her right index finger while playing "Queen of Swords" with a letter opener. Which of the following substances, on contact with injured vascular basement membrane, activates both the coagulation sequence and the kinin system as an initial response to this injury?

A 65-year-old woman has had a fever for the past day. On physical examination her temperature is 39 C and blood pressure 90/50 mm Hg with heart rate of 106/minute. Laboratory studies show a WBC count of 12,220/microliter and WBC differential count of 78 segs, 8 bands, 11 lymphs, and 3 monos. A blood culture is positive for Escherichia coli. Her central venous pressure falls markedly. She goes into hypovolemic shock as a result of the widespread inappropriate release of a chemical mediator derived from macrophages. She develops multiple organ failure. Which of the following mediators is most likely to produce these findings?

A 20-year-old woman sustains an injury to her right calf in a mountain biking accident near Moab. On physical examination she has a 5 cm long laceration on the right lateral aspect of her lower leg. This wound is closed with sutures. Wound healing proceeds over the next week. Which of the following factors will be most likely to aid and not inhibit wound healing in this patient?

A 24-year-old primigravida is late in the second trimester of pregnancy. She experiences the sudden onset of some cramping lower abdominal pain. This is immediately followed by passage of some fluid per vagina along with a foul-smelling discharge. The fetus is stillborn two days later. Examination of the placenta demonstrates extensive neutrophilic infiltrates in the chorion and amnion. Which of the following organisms is most likely to be responsible for these findings?

A 19-year-old man incurs a stab wound to the chest. The wound is treated in the emergency room. Two months later there is a firm, 3 x 2 cm nodular mass with intact overlying epithelium in the region of the wound. On examination the scar is firm, but not tender, with no erythema. This mass is excised and microscopically shows fibroblasts with abundant collagen. Which of the following mechanisms has most likely produced this series of events?

A 45-year-old man has had a fever and dry cough for 3 days, and now has difficulty breathing and a cough productive of sputum. On physical examination his temperature is 38.5 C. Diffuse rales are auscultated over lower lung fields. A chest radiograph shows a right pleural effusion. A right thoracentesis is performed. The fluid obtained has a cloudy appearance with a cell count showing 15.500 leukocytes per microliter, 98% of which are neutrophils. Which of the following terms best describes his pleural process?

A 52-year-old woman with no major medical problems takes a long airplane flight across the Pacific Ocean. Upon arrival at Sydney's Kingsford Smith airport in New South Wales following the flight from Los Angeles, California, she cannot put her shoes back on. There is no pain or tenderness. Which of the following is the most likely explanation for this phenomenon?

In an experiment, a lung tissue preparation is exposed to Mycobacterium tuberculosis organisms. Over the next week, it is observed that granulomas form in the lung. Within the granuloma are found inflammatory cells expressing class II MHC antigens. These cells elaborate cytokines that promote fibroblastic production of collagen within the granulomas. From which of the following peripheral blood leukocytes are these cells bearing class II antigen most likely to be derived?

A 56-year-old man has had increasing difficulty breathing for the past week. On physical examination he is afebrile. Auscultation of his chest reveals diminished breath sounds and dullness to percussion bilaterally. There is 2+ pitting edema present to the level of his thighs. A chest radiograph reveals bilateral pleural effusions. Which of the following laboratory test findings is he most likely to have?

A 44-year-old woman notes a lump in her left breast while taking a shower. Her physician palpates a 3 cm firm, irregular, non-movable mass in the upper outer quadrant of her left breast on physical examination. A fine needle aspiration of this mass is performed, and the cells obtained are examined cytologically and are consistent with infiltrating ductal carcinoma. The mass is removed with lumpectomy along with an axillary lymph node dissection. Which of the following findings will best predict a better prognosis for this patient?

A change in bowel habits prompts a 53-year-old woman to see her physician. On physical examination there are no lesions noted on digital rectal examination, but her stool is positive for occult blood. A colonoscopy is performed and reveals a 6 cm friable mass in the cecum. A biopsy of this mass is performed and microscopic examination shows a moderately differentiated adenocarcinoma. Which of the following findings is most likely to be present in this patient?

A 45-year-old healthy woman has a routine check of her health status. She has no chest pain, cough, or fever. A chest x-ray is taken and shows a peripheral 2.5 cm diameter "coin lesion" in the right mid-lung field. Which of the following biologic characteristics best distinguishes this lesion as a neoplasm, rather than a granuloma?

A clinical study is performed to determine the incidence of cancers in different countries. The data show that persons born in Japan and continuing to reside there have an increased risk for cancer. Which of the following cancers is most likely seen with increased frequency in this population?

A 48-year-old woman goes to her physician for a routine physical examination. A 4 cm diameter non-tender mass is palpated in her right breast. The mass appears fixed to the chest wall. Another 2 cm non-tender mass is palpable in the left axilla. A chest radiograph reveals multiple 0.5 to 2 cm nodules in both lungs. Which of the following classifications best indicates the stage of her disease?

A study is performed to analyze characteristics of malignant neoplasms in biopsy specimens. The biopsies were performed on patients who had palpable mass lesions on digital rectal examination. Of the following microscopic findings, which is most likely to indicate that the neoplasm is malignant?

Review of a series of surgical pathology reports indicates that a certain type of neoplasm is diagnosed as grade I on a scale of I to IV. Clinically, some of the patients with this neoplasm are found to have stage I disease. Which of the following is the best interpretation of a neoplasm with these designations?

A 51-year-old man has worked for 10 years in a factory producing plastic pipe. He has noted weight loss, nausea, and vomiting worsening over the past 5 months. On examination he is afebrile. There is generalized muscle wasting. Laboratory studies show the serum alkaline phosphatase is 405 U/L with AST 67 U/L, ALT 55 U/L, and total bilirubin 1.2 mg/dL. An abdominal CT scan reveals a 12 cm right liver lobe mass. Liver biopsy reveals a neoplasm composed of spindle cells forming irregular vascular channels. The cells demonstrate vimentin positivity and cytokeratin negativity with immunohistochemical staining. Exposure to which of the following substances most likely led to development of this neoplasm?

A child is born with a single functional allele of a tumor suppressor gene. At the age of five the remaining normal allele is lost through a point mutation. As a result, the ability to inhibit cell cycle progression until the cell is ready to divide is lost. Which of the following neoplasms is most likely to arise via this mechanism?

A 22-year-old woman goes to her physician for a routine examination. A palpable nodule is found in the right lobe of her thyroid gland. No lymphadenopathy is noted. A chest x-ray shows no masses. A fine needle aspirate of the nodule is performed and cytologic examination reveals cells present consistent with a papillary carcinoma of the thyroid. There are no other family members affected by this disorder. She works as a secretary for an accounting firm part time and is earning a college degree. Which of the following findings would you consider most relevant in her past history to indicate a risk factor for this neoplasm?

A 50-year-old man has felt vague abdominal discomfort for the past 4 months. On physical examination he has no lymphadenopathy, and no abdominal masses or organomegaly can be palpated. Bowel sounds are present. An abdominal CT scan shows a 20 cm retroperitoneal soft tissue mass obscuring the left psoas muscle. A stool specimen tested for occult blood is negative. Which of the following neoplasms is this man most likely to have?

A 52-year-old man has had increasing fatigue for the past 6 months. On physical examination he has a palpable spleen tip. Laboratory studies show a WBC count of 189,000/microliter. The peripheral blood smear shows many mature and immature myeloid cells present. Cytogenetic analysis of cells obtained via bone marrow aspiration reveals a t(9:22) translocation. This translocation leads to formation of a hybrid gene that greatly increases tyrosine kinase activity. Which of the following genes is most likely translocated to cause these findings?

A clinical study is performed of oncogenesis in human neoplasms. It is observed that some neoplasms appear to develop from viral oncogenesis, with serologic confirmation of past viral infection. Which of the following neoplasms is most likely to arise in this manner?

An experiment is designed to study the genetics of cancer. The study will link the appearance of cancer to specific gene abnormalities. Which of the following forms of cell molecular analysis is most useful to identify gene alterations involved in carcinogenesis?

A 29-year-old woman with a history of multiple sexual partners over the last 15 years has a routine physical examination with no abnormal findings. On pelvic examination, the cervix shows no abnormalities, but a Pap smear is taken and dysplastic cells are reported to be present. A cervical biopsy is performed and shows a low grade squamous intraepithelial lesion (LSIL), also known as cervical intraepithelial neoplasia dysplasia (CIN). Which of the following is the most therapy for this lesion?

A 64-year-old man has noted a 5 kg weight loss along with increasing fatigue over the past year. He has experienced dull abdominal pain for the past week. He has developed abdominal distention with lack of stools in the past two days. On physical examination, bowel sounds are reduced. An abdominal CT scan reveals a mass involving the descending colon. At laparotomy, a partial resection of the left colon is performed, with removal of an encircling mass. Microscopically, the mass is found to be a moderately differentiated adenocarcinoma. Which of the following laboratory test findings is most likely to be present in this man?

A 14-year-old healthy girl has a 0.3 cm reddish, slightly raised nodule on the skin of the upper part of her chest found on a routine physical examination. She states that this lesion has been present for years and has not appreciably changed in size or color. Which of the following neoplasms is this nodule most likely to be?

A 56-year-old man has had a chronic cough for the past year. He is a non-smoker. He had an episode of hemoptysis 3 days ago. No abnormal findings are noted on physical examination. A chest x-ray demonstrates a 6 cm perihilar mass. A sputum sample is collected, and the sputum cytology report reads "Atypical cells present suggestive of squamous cell carcinoma." Which of the following environmental exposures is most likely to be associated with these findings?

A 60-year-old man who has a 90 pack year history of cigarette smoking has had a chronic cough for the past 10 years. He has begun to lose weight (3 kg) during the past year. No abnormal findings are noted on physical examination. He has a chest radiograph that reveals a right hilar mass. A sputum cytology shows atypical, hyperchromatic squamous cells. What is the most common initial pathway for metastases from this lesion?

A 55-year-old man dies after a year-long illness. At autopsy her liver contains multiple tumor masses from 2 to 5 cm in size that are firm and tan and that grossly exhibit umbilication with central necrosis. The surrounding hepatic parenchyma appears normal. Which of the following characteristics of neoplasia is best illustrated by these findings?

A 59-year-old man has had a worsening cough with chest pain for the past 6 months. On physical examination he has no remarkable findings. A chest x-ray shows a 3 cm left lung mass. A sputum cytology specimen yields cells diagnosed as a squamous cell carcinoma. A mediastinoscopy is performed and reveals metastases in a lymph node. He is given radiation therapy, and the mass diminishes in size. Which of the following cellular mechanisms is most likely to account for this tumor response?

A 60-year-old woman has a firm mass with irregular borders felt in her left breast on a routine physical examination. A fine needle aspiration is performed and microscopic examination shows malignant cells. A left mastectomy with axillary lymph node dissection is performed. A tissue sample of this neoplasm is submitted for analysis by flow cytometry. Which of the following does flow cytometric analysis most likely provide?

A 35-year-old woman had a firm nodule palpable on the dome of the uterus six years ago recorded on routine physical examination. The nodule has slowly increased in size and now appears to be about twice the size it was when first discovered. By ultrasound scan it is solid and circumscribed. She remains asymptomatic. Which of the following neoplasms is she most likely to have?

A 15-year-old boy has had lumps in his right neck for the past 5 months. On physical examination there is painless lymphadenopathy in the right cervical region. One of the lymph nodes is biopsied and on microscopic examination shows many lymphocytes that are large, with clumped chromatin and occasional mitoses. The characterization of this population of lymphocytes as a neoplasm is best accomplished by which of the following methods?

A previously healthy 42-year-old man has a skin nodule on his right hand that has become larger and darker with more irregular outlines over the past 3 months. On physical examination this lesion is a 1.2 cm diameter, darkly pigmented, and slightly raised nodule on the dorsum of his right hand. No other skin lesions are noted. Three nontender enlarged lymph nodes are palpable in the right axilla. The lesion is excised and microscopic examination shows a neoplasm composed of darkly pigmented polygonal and spindle cells. Which of the following risk factors is most important for development of this neoplasm?

A a 27-year-old woman in excellent health has a routine health maintenance examination. A 2 cm firm, rounded mass is palpable beneath the skin of the left forearm. She has no difficulty using the arm and there is no associated pain with the mass, either in movement or on palpation. The overlying skin appears normal. The mass does not change in size over the next year. Which of the following neoplasms is she most likely to have?

A 41-year-old woman has noted a foul-smelling vaginal discharge for 3 weeks. On physical examination there is an exophytic 3 cm mass involving the ectocervix. Pap smear testing is performed; she has never had a previous Pap smear. Cytologic changes are present on this Pap smear that are consistent with squamous cell carcinoma. She is found to have a positive serologic test for syphilis. Her serum glucose is 157 mg/dL. She has been a commercial sex worker in the past. Which of the following is the most likely risk factor for her cervical carcinoma?

A 60-year-old man with an 80 pack year history of smoking experiences an episode of hemoptysis. On physical examination he has puffiness of the face, some pedal edema, bruises of the skin, and a blood pressure of 165/100 mm Hg. A chest radiograph reveals a 5 cm right upper lobe lung mass. A fine needle aspirate of this mass yields cells consistent with small cell anaplastic ("oat cell") carcinoma. A bone scan shows no metastases. Immunohistochemical staining of the tumor cells is likely to be positive for which of the following hormones?

A 45-year-old woman has noted a lump on her left shoulder that has enlarged over the past 4 months. On physical examination there is an enlarged, non-tender supraclavicular lymph node. A biopsy of the node is performed and on microscopic examination there is a metastatic neoplasm. Which of the following is the most likely primary neoplasm?

A 59-year-old man has had fatigue for the past year. The only abnormal physical examination finding is a positive stool guaiac test. Laboratory studies show a CBC with Hgb 10.0 g/dL, Hct 29.8&, MCV 73 fL, platelet count 300,000/microliter, and WBC count 8700/microliter. He is found on colonoscopy to have a 4 cm mass lesion arising on the mucosal surface of the transverse colon. An abdominal CT scan shows hepatic masses. He receives therapy with cetuximab directed at vascular endothelial growth factor (VEGF). Which of the following cell signaling pathways is most affected by this therapy?

Columnar epithelial cells from the colonic mucosa are studied to identify abnormalities in cell signaling pathways. Abnormal epithelial cells from colonic adenocarcinoma are shown to have a mutation that blocks hydrolysis of GTP-bound active RAS. Normal columnar cells have active RAS protein that undergoes hydrolysis to the inactive GDP-bound form. Which of the following signaling pathways is most likely abnormally stimulated in the carcinoma cells?

A 52-year-old woman feels a lump in her right breast and goes to her physician. On physical examination there is a 3 cm right breast mass fixed to the chest wall. This mass is biopsied and on microscopic examination shows nests of cells with marked hyperchromatism and pleomorphism. These cells are estrogen receptor positive. Flow cytometry is performed. Compared with surrounding non-neoplastic stromal cells, the neoplastic cells are more likely to be in which of the following phases of the cell cycle?

A 70-year-old man has an episode of hematemesis. Upper GI endoscopy reveals an irregular 4 cm gastric antral ulceration. Biopsies are performed and microscopically reveal adenocarcinoma. Molecular analysis shows DNA hypermethylation of the CDKN2 complex. Through which of the following mechanisms has this abnormal gene expression most likely occurred?

In an experiment, it is observed that chronic, increased exposure to ionizing radiation results in damage to cellular DNA. As a consequence, a protein is now absent that would arrest the cell in the G1 phase of the cell cycle. Subsequent to this, the cell is transformed to acquire the property of unregulated growth. The absent protein is most likely the product of which of the following genes?

A 50-year-old woman notes a lump in her left breast. She goes to her physician's assistant, who palpates a 2 cm firm mass in her left breast. A fine needle aspiration biopsy is performed, and on microscopic examination a ductal carcinoma is seen. A poorer prognosis for the patient is most closely associated with which of the following findings?

An epidemiologic study is performed to determine risk factors for development of malignant neoplasms. A statistical analysis of pre-existing medical conditions is done. Some pre-existing conditions are observed to precede development of malignant neoplasms, while others do not. Which of the following conditions is most likely to be statistically unrelated to subsequent malignancy?

A 35-year-old man has noted several 1 to 2 cm reddish purple, nodular lesions present on the skin of his right arm which have increased in size and number over the past 3 months. The lesions do not itch and are not painful. He has had a watery diarrhea for the past month. On physical examination he has generalized lymphadenopathy and oral thrush. Which of the following infections is most likely to be related to the appearance of these skin lesions?

A 66-year-old woman has noted increasing abdominal girth for 3 months. On examination there is a fluid wave. Paracentesis yields cloudy fluid that cytologically contains clusters of malignant cells. An abdominal CT scan shows bilateral cystic and solid pelvic masses and multiple peritoneal nodules. She is treated with chemotherapy with an initial response, but a year later there is still residual tumor. Which of the following parameters of the neoplastic cells best predicts her diminished chemotherapy response?

A 49-year-old man complains of pain in his left thigh for 3 months. On physical examination his thigh is increased in size, compared to the right. A plain film radiograph reveals the presence of a 15 cm solid mass that does not appear to arise from bone, but it does have infiltrative margins. A biopsy of this mass is taken, and on microscopic examination the mass is composed of highly pleomorphic spindle cells. Which of the following immunohistochemical markers is most likely to be demonstrated in the cells of this mass?

A clinical study is performed with patients who had a diagnosis of breast cancer. Characteristics of the grade, stage, molecular biology, and histologic type are analyzed. Of the following characteristics, which is most likely to be associated with the best prognosis for these patients?

A 66-year-old man has noted darker urine for the past 2 weeks. A urinalysis shows hematuria. He is referred to a urologist who performs cystoscopy. A 3 cm mass is found in the dome of the bladder. Biopsies of the mass are taken and on microscopic examination show a urothelial carcinoma. Cells of this neoplasm demonstrate a single mutation causing cellular inability to hydrolyze GTP, thus resulting in cellular transformation. Which of the following oncogenes is most likely implicated in this case?

A 44-year-old woman who has had multiple sexual partners for the past 30 years has an abnormal Pap smear with cytologic changes suggesting human papillomavirus (HPV) infection. Without treatment, she is most likely to develop which of the following lesions?

In an epidemiologic study, "fallout" from nuclear bomb testing and from nuclear power plant disasters is observed to have released radioactive isotopes into the environment. One of these isotopes is found to be strontium-90. It is observed that the strontium-90 in soils goes into the food chain and eventually contaminates milk products. This contamination is most likely to increase the risk for which of the following neoplasms?

A clinical trial of a new chemotherapy protocol is performed involving patients with lung carcinoma. It is observed that a response occurs that leads to DNA strand breakage and carcinoma cell death. The primary carcinomas are initially observed to decrease in size following therapy. However, after 3 months, the carcinoma is no longer regressing with this therapy. Altered expression of which of the following by the neoplastic cells has most likely resulted in this reduced response?

In an experiment, biologic characteristics of neoplastic and non-neoplastic cells are analyzed in culture. It is observed that cell division in cells derived from malignant neoplasms, but not in normal cells, is aided by the presence of an enzyme which repairs progressive chromosomal shortening. The lack of chromosomal shortening allows the malignant cells to undergo many more divisions than the normal cells. Which of the following enzymes is most likely to have this effect?

A 62-year-old man has complained of pain on urination for the past week. He is afebrile. On cystoscopy, a slightly erythematous 1 cm diameter area is seen on the bladder mucosa. This area is biopsied and on microscopic examination shows cells with marked hyperchromatism and increased nuclear/cytoplasmic ratio involving the full thickness of the epithelium. However, these changes are confined to the epithelium above the basement membrane. Which of the following terms best describes these biopsy findings?

A 32-year-old woman has noted dull pelvic pain for the last two months. On physical examination there is a mass palpated in the right lower quadrant. An abdominal ultrasound reveals an 8 cm mass involving the right ovary. The mass is surgically excised. On gross inspection, the surface of the mass is smooth, is not adherent to surrounding pelvic structure, and is cystic and filled with hair on sectioning. On microscopic examination there is squamous epithelium, tall columnar glandular epithelium, cartilage, and fibrous connective tissue. Which of the following neoplasms is she most likely to have?

A 54-year-old woman has an episode of coughing with blood-streaked sputum. On physical examination she appears cachectic. A chest x-ray shows an irregular mass lesion in the right lung. A transbronchial biopsy is done and on microscopic examination shows small cell anaplastic carcinoma. She is treated with a multidrug chemotherapy regimen and has a partial response. However, metastatic disease develops eight months later. A second chemotherapy protocol is tried, but no response is noted. Which of the following is the most likely reason for failure of the second protocol to elicit a response?

A previously healthy 66-year-old man has been feeling tired for 5 months. He goes to his physician, who performs a complete physical examination, including stool guaiac, which is positive. A colonoscopy is performed, and a large, sessile 4.5 cm mass with surface ulceration is found in the cecum. A biopsy of this mass microscopically shows irregular glands with crowded, tall columnar cells having marked nuclear hyperchromatism. Which of the following gene alterations is he most likely to have?

An 8-year-old boy has complained of difficulty swallowing for the past month. On physical examination he has a palpable, firm mass in the right neck. A head CT scan reveals a 7 cm solid soft tissue mass lateral to the esophagus on the right. A biopsy of this mass demonstrates pleomorphic spindle cells that are cytokeratin negative, CD45 negative, and vimentin positive. Which of the following neoplasms is he most likely to have?

A 53-year-old woman feels a lump in her right breast. Her physician palpates an irregular 3 cm mass that is not movable because it appears fixed to the overlying skin, which is retracted. A mastectomy is performed and the pathologist on sectioning the breast finds a 3 x 3.5 cm ovoid mass that does not have discrete borders, but appears to infiltrate into the surrounding fibrofatty breast stroma. The mass is firm, white, and has a fibrous consistency. Which of the following features is most likely demonstrated by the gross appearance of this mass?

A 66-year-old man has a routine physical examination and a stool sample is positive for occult blood. He undergoes colonoscopy and a 5 cm sessile mass is present in the sigmoid colon. Biopsy of the mass yields a diagnosis of adenocarcinoma. A chest x-ray shows multiple 1 to 3 cm nodules in both lungs. Presence of which of the following in the neoplastic cells is most likely to explain the formation of lung nodules?

A healthy 22-year-old woman undergoes a routine physical examination. A discrete, firm, rubbery, movable mass is found in the left breast. She has no axillary lymphadenopathy. The skin overlying the breast and the nipple appear normal. Which of the following neoplasms is most likely to be present?

An epidemiologic study is performed involving patients of Asian ancestry with long-standing Epstein-Barr virus (EBV) infection. It is observed that these patients have an increased risk for development of malignant neoplasms in adulthood. Which of the following neoplasms is most likely to be found in these patients?

A clinical study is performed involving children who have developed skin cancers, including squamous cell carcinomas and basal cell carcinomas. Molecular analysis of their cancer cells shows defective DNA repair from loss of nucleotide excision repair gene expression. Which of the following genes is most likely mutated in these chilren?

A 29-year-old woman feels a nodule in her neck. On examination there is a firm 2 cm mass in the right lobe of her thyroid. A fine needle aspiration shows cells consistent with papillary carcinoma. 2 years ago she had a lobular carcinoma excised from her left breast. Her 31-year-old sister was recently diagnosed with endometrial carcinoma. A 34-year-old cousin has had colon cancer. Over 3 generations, 6 of 24 close relatives have had a malignancy, most diagnosed before age 35. Which of the following most likely explains the increased risk for cancer in these people?

A study of malignant neoplasms reveals that some of them have a greater potential for invasion and metastases. Analysis of the cells of cancers that have metastasized reveals a mutation which results in decreased cell surface expression of E-cadherin. Which of the following genes is most likely mutated to produce these findings?

An experiment is conducted in which proliferating cells are subjected to ionizing radiation. The ionizing radiation leads to arrest in a checkpoint that monitors completion of DNA replication. It is observed that there are increased numbers of chromosomal abnormalities in these cells. Which of the following is the checkpoint affected by the ionizing radiation?

A 4-year-old child was born at term, with no congenital anomalies. She is now only 70% of normal body weight. On examination she shows dependent edema of the lower extremities as well as an enlarged abdomen with palpable fluid wave. Her desquamating skin shows irregular areas of depigmentation, and hyperpigmentation. Which of the following nutritional problems is most likely present in this child?

A 32-year-old man has a history of multiple and recurrent pulmonary infections since childhood. He also has noted foul smelling stools for the past 10 years. Laboratory studies show an elevated sweat chloride test. He has a quantitative stool fat of 10 g/day. A deficiency state involving which of the following nutrients is most likely to develop in this patient?

A 45-year-old woman has developed red, roughened skin in sun-exposed areas over the past 2 years. She also has a chronic, watery diarrhea. On physical examination she exhibits memory loss with confusion. These findings are most consistent with which of the following vitamin deficiencies?

A 5-year-old child has complained of pain in his legs for the past year. On physical examination, there is bowing deformity of his lower extremities. Plain film radiographs of his lower legs shows widened epiphyses and bowing of tibiae. Bone mineral density appears normal, consistent with failure of osteoid matrix formation. Which of the following vitamin deficiencies is this child most likely to have?

A clinical study of diet in pregnancy is conducted. It is observed that pregnant women who do not get a diet that includes green, leafy vegetables develop a specific nutritional deficiency that affects their developing fetuses. Which of the following abnormalities is most likely to be found with increased frequency in these fetuses?

A clinical study is performed involving dietary iron metabolism in adults. It is observed that intestinal absorption of iron can be enhanced in patients with iron deficiency anemia by supplementing their diet with another nutrient. Which of the following vitamins is most likely to have this effect?

A 41-year-old man has had increasing dyspnea for the past year. On physical examination he has diffuse crackles at lung bases. A chest x-ray shows pulmonary edema and cardiomegaly. Echocardiography shows an ejection fraction of 40%. Laboratory studies show hemoglobin 14 g/dL, hematocrit 42%, and WBC count 8320/microliter. A deficiency in which of the following vitamins is most likely to produce these findings?

A 49-year-old man has a 20 year history of chronic alcohol abuse. He has had worsening problems with ambulation for the past year. On physical examination his gait is ataxic. MR imaging of the brain shows diminished size of the mamillary bodies. He is most likely to have a deficiency of which of the following vitamins?

A 34-year-old primigravida is in her 8th month of gestation. She is feeling increasingly tired and weak. Laboratory studies include a CBC which shows Hgb 9.7 g/dL, Hct 28.8%, MCV 71 fL, platelet count 289,000/microliter, and WBC count 5600/microliter. On the peripheral blood smear, the RBCs show increased variation in size and shape, with many that are hypochromic and microcytic. Which of the following dietary deficiencies is she most likely to have?

A clinical study is performed to compare the risk for health problems in obese persons with a BMI >30, compared with a control group of persons with a BMI between 20 and 25. Persons in these two groups are followed for 20 years. Which of the following conditions is most likely to appear equally in both groups?

A study is performed involving the relationship of diet and cancer. It is observed that inclusion of certain foods in the diet is associated with a decreased risk for subsequent development of cancer. Which of the following foods is most likely to have this risk-reducing effect?

A dietary study is performed that assesses risks for hypertension. It is observed that increased consumption of sodium in the diet is correlated with elevated blood pressure. Of the following food items, which one has the greatest amount of sodium?

A 42-year-old man with a 19-year history of chronic alcohol abuse has noted during the past year that he has bruising with minimal trauma. On physical examination he has abdominal enlargement with a fluid wave. He has pitting edema to the knees. He has palmar erythema. Laboratory studies show he has a prothrombin time of 30 seconds. His hemoglobin is 13.8 g/dL, hematocrit 44.4%, MCV 94 fL, platelet count 229,000/microliter, and WBC count 6630/microliter. Which of the following nutrients is most likely to be of benefit in treating this man?

A study is performed to determine dietary sources of vitamin A. It is observed that some commonly available foods have more vitamin A than others. Which of the following is most likely to provide the best source for vitamin A in the diet?

A 15-year-old girl has been under a physician's care for the past year after diagnosis of anorexia nervosa. Her BMI is now 18. On physical examination she has cheilosis. Laboratory studies show hemoglobin 13.7 g/dL, hematocrit 41.0%, MCV 88 fL, platelet count 191,055/microliter, and WBC count 4930/microliter. Her serum glucose is 66 mg/dL. Which of the following nutrient deficiencies is most likely to cause her findings?

A 36-year-old woman goes to the health food store to buy dietary supplements that she is convinced will help her to be more healthy and live longer. Instead, a year later she has increasing headaches, joint pain, nausea, vomiting, and weight loss. On physical examination she is noted to have dryness of the oral mucosa, and a mild degree of papilledema is noted on funduscopic examination. A radiograph of her hands shows bony hyperostosis. An excessive intake of which of the following nutrients is most likely responsible for her findings?

A 39-year-old woman has been on and off diets for the past 10 years trying to lose weight. She has had no major illnesses during this time. Her BMI has ranged from 25 to 31 over that time. Which of the following problems is her pattern of dieting most likely to cause?

A 5-year-old child develops gradual loss of vision over the past 2 years resulting in blindness. On physical examination there is bilateral keratomalacia and corneal scarring. This child's blindness is most likely to have been prevented by adequate dietary intake of which of the following vitamins?

A 45-year-old man has had increasing abdominal enlargement over the past year. On physical examination there is an abdominal fluid wave. An abdominal CT scan shows a small nodular liver with a 10 cm mass in the right lobe. Laboratory studies shown a serum albumin of 2.9 g/dL. Serologic testing is positive for hepatitis B and C. He does not abuse ethanol. Which of the following toxins is most likely to contribute to the development of this man's liver disease?

An 11-month-old infant is only 60% of ideal body weight. The baby is proportionately small in size. Upon physical examination, the baby is listless and does not respond with vocalization when touched. A small purplish contusion is noted over the right lower extremity. Which of the following is the most likely diagnosis?

A 65-year-old woman has felt increasingly fatigued during the past 9 months. On physical examination she has decreased sensation to touch in her lower extremities bilaterally. Laboratory studies show hemoglobin 10.1 g/dL, hematocrit 31.2%, and MCV 120 fL. Microscopic examination of the peripheral blood smear shows red blood cells that have macrocytosis and neutrophils with hypersegmentation of nuclei. Laboratory testing for which of the following nutrients is most likely to show a deficiency state?

A 27-year-old woman has been having particularly heavy menstrual periods for the past year. She is becoming progressively fatigued. She then becomes pregnant. She receives no prenatal care. She delivers a term baby. During the delivery, bleeding is excessive. Which of the following nutrient deficiencies is most likely to be present in both mother and baby?

A 40-year-old man has a body mass index of 40. His BMI was increased, even as a child. He has deranged leptin signaling by steatocytes. Which of the following complications is he most likely to develop?

A 23-year-old man has a positive tuberculin skin test and a chest radiograph showing upper lobe densities. He is started on antitubercular therapy with isoniazid, rifampin, and ethambutol. Over the next 4 months he develops paresthesias of his hands and feet. A deficiency of which of the following vitamins is most likely causing this complication of therapy?

While at a family reunion, parents are talking about their children. One family unit notes that none of their children has had any dental caries, though all of the children have all had the same childhood infections and have similar dietary habits. They all brush their teeth regularly. Children in other family units have had multiple visits to the dentist for treatment of dental caries. Which of the following is most likely to account for this observation?

A 21-year-old G3 P2 woman gives birth at term at home. The infant has Apgar scores of 8 and 9 at 1 and 5 minutes. The newborn is initially doing well, but at 3 days of life there is bleeding from the umbilical cord stump, and ecchymoses are observed over the buttocks. This is followed by seizure activity. Which of the following vitamin deficiencies is most likely to be present in this infant?

A 54-year-old man expects to halt the ravages of aging. He does a search on the internet for information about prevention of aging. He finds multiple sites recommending dietary supplements with anti-aging properties. Some of these sites also indicate that a deficiency of a particular vitamin may lead to neurologic problems similar to cobalamin (vitamin B12) deficiency, but without development of pernicious anemia. Persons with liver and biliary tract disease are also more likely to be deficient in this nutrient. Which of the following vitamins is most likely to have these properties?

A 56-year-old man has paresthesias of the lower extremities, worsening over the past 3 years. A CBC shows: Hgb 10.0 g/dL, Hct 30.6%, MCV 121 fL, platelets 233,000/microliter, and WBC count 8100/microliter. Examination of the peripheral blood smear shows macro-ovalocytosis of the RBCs and hypersegmentation of the neutrophils. Which of the following nutritional deficiencies is he most likely to have:

A healthy 19-year-old primigravida is in the 12th week of her pregnancy when she develops vaginal spotting of blood and mild cramping abdominal pain. The pregnancy up to that point has been uncomplicated. On physical examination she is afebrile. There is minimal vaginal bleeding but no exudate. A spontaneous abortion occurs a day later. Which of the following conditions is most likely to produce these findings?

A 26-year-old G4 P3 woman gives birth via normal spontaneous vaginal delivery at term. The infant has Apgar scores of 9 and 10 at 1 and 5 minutes and weighs 2950 gm. The placenta is delivered 10 minutes later and weighs 500 gm. Examination of the placenta reveals that the umbilical attachment to the infant is 100 cm long. Which of the following additional abnormalities is most likely to have been observed at the time of delivery?

A 19-year-old woman is G2 P1. Her previous gestation resulted in a normal term birth at home. Her current pregnancy results in the birth of a 2990 gm baby at 35 weeks. At birth the infant appears hydropic and icteric, but no congenital anomalies are noted. The baby's hemoglobin is 8.5 g/dL. The placenta is also hydropic, but microscopic examination of the placenta shows no inflammation of either fetal membranes or placental villi, and there is no meconium staining. Which of the following problems in the mother is the most likely explanation for the subsequent findings in the infant?

No fetal movement has been felt for the past day by a 25-year-old gravida 3 para 2 woman in her 39th week of pregnancy. Prior to that time, the pregnancy was uncomplicated. The baby is stillborn upon vaginal delivery a day later, after rupture of membranes occurs. Microscopic examination of the placenta reveals marked acute chorioamnionitis. Which of the following infectious agents is most likely responsible for these findings?

A 17-year-old primigravida has noted no fetal movement during her pregnancy, and she is now at 18 weeks gestation. Oligohydramnios is noted on ultrasound scan, making it difficult to visualize fetal internal organs, but the size of the baby appears consistent for 18 weeks gestational age. Following a counseling session with their physician, the parents decide to proceed with prostin induction for a medically indicated termination of pregnancy. Autopsy reveals no external anomalies upon examination of the stillborn male. Which of the following findings is most likely to explain this deformation sequence?

A 32-year-old G2 P1 woman has an uncomplicated vaginal delivery of a 30 week gestational age male infant. Apgar scores of 5 and 7 at 1 minute and 5 minutes are recorded at the time of birth. The baby then begins to exhibit increasing respiratory difficulty in the next hour, culminating in the need for intubation and mechanical ventilation. Which of the following laboratory tests during gestation is most likely to predict the complication observed in this infant?

A 33-year-old G3 P2 woman gives birth at 38 weeks gestation to a male infant who weighs 2270 gm. Apgar scores are 7 and 9 at 1 and 5 minutes after birth. This neonate has no external anomalies present on physical examination except that he appears somewhat disproportionate, with a head size more appropriate for gestational age than body size. The pregnancy was uncomplicated. Which of the following conditions is most likely to account for these findings?

A genetic counselor elicits the history that three adult males and one adult female in a family of 10 over 3 generations are mentally retarded, the males more severely so. Physical examination of these affected males reveals no major morphologic anomalies, though their testes appear to be slightly enlarged, without mass lesions present. These males have been healthy, without a history of major illnesses. Which of the following genetic abnormalities is the most likely etiology for these findings?

A 21-year-old G2P1 woman feels that she is large for dates. She has felt fetal movement for the past week. She has a screening ultrasound scan performed at 16 weeks gestation. This ultrasound reveals that there is markedly increased amniotic fluid (polyhydramnios). Which of the following fetal abnormalities is most likely to cause this finding?

A 25-year-old gravida 3 para 2 woman gives birth at term to twins. Twin A weighs 2290 gm and twin B weighs 2910 gm. Twin A is pale while twin B exhibits plethora with hydrops fetalis. Which of the following is the most likely cause for these findings?

A 24-year old primigravida gives birth at term to an infant with Apgar scores of 8 and 10 at 1 and 5 minutes. No congenital anomalies are noted. The infant develops abdominal distention over the first week of life. An ultrasound scan is performed that suggests the presence of meconium ileus. Subsequently, the infant has persistent steatorrhea during childhood. Which of the following laboratory test findings is most likely related to this child's underlying disease?

A 20-year-old primigravida experiences a stillbirth at 28 weeks gestation. An autopsy is performed, and the fetus is found to have a hemivertebra, anal atresia, tracheo-esophageal fistula, and renal multicystic dysplasia. The placenta appears normal, and no amnionic bands are seen and no body wall defects are present. Chromosome analysis reveals a 46, XX karyotype. There is no history of any prior birth in this family with such findings. Five subsequent pregnancies in this woman yield normal term births. Which of the following descriptive terms best applies to the spectrum of abnormalities in this stillborn fetus?

A 23-year-old G3 P2 woman gives birth to a normal term male infant. The pregnancy was uncomplicated. Apgar scores are 10 and 10 at 1 and 5 minutes following birth. The infant weighs 2930 gm and the placenta weighs 550 gm. Which of the following umbilical cord findings is most likely to be found on gross and microscopic examination of this infant's placenta?

A 20-year-old G2 P1 woman has had an uncomplicated pregnancy, but she has received no prenatal care. She goes into labor at term. During the birth process, she experiences sudden extensive hemorrhage evidenced by profuse vaginal bleeding. The baby is liveborn and weighs 2790 gm. Which of the following is the most likely diagnosis?

A clinical study is performed to determine when fetal malformations are most likely to occur during gestation when mothers who have not received prior immunization become infected by rubella virus. The study examines abortuses for congenital anomalies. When during gestation are malformations most likely to arise with rubella infection?

An 18-year-old primigravida gives birth at 38 weeks gestation via uncomplicated vaginal delivery. The baby weighs 1500 gm and the placenta weighs 330 gm. No congenital anomalies are noted. Which of the following conditions is most likely to produce these findings?

A 7-month-old infant has failure to thrive, with vomiting and diarrhea noted since 1 month of age. Developmental neurologic milestones are not being met. A physical examination reveals hepatomegaly. The eyes show cataract formation in the crystalline lenses. The baby dies of fulminant Escherichia coli septicemia at 8 months of age. Which of the following congenital abnormalities is most likely to produce these findings?

A 27-year-old G4 P3 woman gives birth at term to a 2900 gm infant with Apgar scores of 9 and 10 at 1 and 5 minutes following birth. Since 1 of 3 siblings has had a prior diagnosis of a congenital disease, this infant is tested for the deltaF508 mutation of the CFTR gene, which is found to be present. Which of the following conditions is most likely to complicate this infant's neonatal period?

A 10-year-old child has joints that show marked hypermobility, and her skin is hyperextensible. Her height and weight are at the 50th percentile. These features are most suggestive of which of the following inherited diseases?

A 24-year-old primigravida has some cramping pain followed by passage of some fluid along with a foul-smelling discharge late in the second trimester at 24 weeks gestation. The fetus is stillborn 2 days later. Examination of the placenta microscopically show neutrophilic infiltrates within the chorion and amnion. Which of the following organisms is most likely to be responsible for these findings?

A 25-year-old woman has a workup for infertility. She has never experienced menarche. On physical examination she is short, with a broad chest and a webbed neck. She has normal intelligence. A blood sample is obtained for chromosome analysis. Which of the following karyotypes is she most likely to have?

A study is performed to analyze causes for fetal loss. Autopsy findings from abortuses and stillborn fetuses are collected. Which of the following conditions is most likely found to compromise fetal survival the most prior to the time of delivery:

A 30-year-old G2 P1 woman gives birth at 37 weeks gestational age. Apgar scores are 8 at 1 minute and 10 at 5 minutes. The infant is noted to weigh 4450 gm. However, within 3 hours after delivery, the infant is irritable and exhibits seizure activity. Laboratory studies show that the infant's blood glucose is 22 mg/dl. Which of the following is the most likely diagnosis?

A clinical study is performed involving persons who have an inherited genetic mutation involving a large gene that encodes for a structural protein known as fibrillin. Affected persons develop aortic root dilation, mitral valve prolapse, and dislocated ocular lenses. Of the following statements regarding this inherited condition, which is the most accurate?

A 25-year-old primigravida experiences a spontaneous abortion at 13 weeks gestation. She had an uncomplicated pregnancy up to that time. There is no family history of congenital abnormalities. Her nutritional status is normal. Which of the following is the most likely cause for her fetal loss?

A 39-year-old G3 P2 woman has felt minimal fetal movement since 16 weeks gestation. She gives birth at 30 weeks gestation to a stillborn male. At autopsy this fetus is found to have lungs that are only 1/3 the weight of normal for that gestational age. There are no external anomalies noted, but the baby's nose is flattened and there are prominent infraorbital creases, as well as contractures of the arms and varus deformities of the feet. Which of the following is most likely to cause these findings?

A 31-year-old G2 P1 woman has an uncomplicated pregnancy and gives birth at term. Examination of the newborn reveals aniridia. The external genitalia are ambiguous. Chromosome analysis reveals a 46, XY karyotype. The infant does not meet developmental milestones and it is apparent by age 2 that profound mental retardation (IQ <20) is present. At the age of 3 the child is found to have a left renal mass. Which of the following conditions is this child most likely to have?

A 25-year-old mother notes that her 18 month old child is not keeping up with the normal growth curve for the past 5 months. She has noted that her child has not been feeding well over that time. The baby's abdomen seems larger than it should be. On physical examination, there is a palpable firm left upper quadrant mass. Which of the following is the most likely diagnosis in this child?

A 21-year-old primigravida gives birth at 29 weeks gestation. At one minute after birth, the baby appears blue in color, has a heart rate of 40/minute, exhibits no respirations, is flaccid with no movement, and does not respond to stimulation. Which of the following is the baby's Apgar score most likely to be at 1 minute?

A clinical study reveals that malformations occur in some, but not all, fetuses whose mothers contract a certain viral infection during pregnancy. Which of the following maternal exposures is most likely to result in cardiac malformation in the fetus?

An autopsy study is conducted to determine distinguishing features for abortuses and stillbirths, since there are medicolegal ramifications to such a classification. A fetal death certificate is required when the findings suggest survival in utero to 20 weeks gestation. Which of the following features is most likely to be present in an "abortion" rather than a "stillbirth"?

A 33-year-old G3 P2 woman gives birth to a male infant at 32 weeks gestation. The baby weighs 3550 gm. No congenital anomalies are noted. An episode of hypoglycemia is treated with intravenous glucose. An hour after birth, the infant develops respiratory distress. Intubation with positive pressure ventilation is performed to maintain adequate oxygenation. Which of the following prenatal tests on the mother would most likely have predicted this outcome?

A 20-year-old primigravida has a normal prenatal course until ultrasound at 19 weeks gestation reveals an enlarged fetal heart and swelling of soft tissues. The infant is born prematurely at 36 weeks gestation. On newborn examination the infant is severely hydropic. Laboratory studies show oxygen saturation >90%, severe anemia, but no hyperbilirubinemia. Which of the following is the most likely cause for the infant's findings?

A 16-year-old primigravida gives birth to a 38 week gestational age male. At the time of delivery, it is noted that the umbilical cord has a single artery and vein. Which of the following is the most significant result of this finding in the cord?

A 24-year-old G1 P1 woman gives birth to a male infant at 36 weeks gestation. Microscopic examination of the placenta following delivery reveals that numerous polymorphonuclear leukocytes are present in the fetal membranes (both chorion and amnion). Which of the following is most likely to be associated with this placental finding?

A 45-year-old woman is worried about having a child with Down syndrome if she becomes pregnant. What procedure can you do in the course of giving prenatal care that will best allow you to determine if the fetus has Down syndrome?

A 32-year-old woman gives birth at 31 weeks gestation. Within an hour following delivery, the neonate develops respiratory distress and expires despite intubation and mechanical ventilation. An autopsy is performed. The lungs are firm and airless; on microscopic examination the lungs demonstrate extensive pink hyaline membranes within alveoli. Which of the following conditions is most likely to cause these findings?

A 30-year-old G2 P1 woman has felt minimal fetal movement by 17 weeks gestation. On examination the uterine size appears small for dates. An ultrasound scan shows fetal growth retardation. Amniocentesis is performed and chromosome analysis on fetal cells reveals a 47 XX, +13 karyotype. Which of the following ultrasound findings is most likely to be present in this fetus?

A 29-year-old G5 P4 woman gives birth via vaginal delivery at 40 weeks gestation. The infant boy weighs 3020 gm. The placenta is delivered 10 minutes later and weighs 540 gm. Upon gross inspection, the fetal surface of the placenta has a greenish appearance. Which of the following is the most likely diagnosis for this placental appearance?

A 16-year-old primigravida delivers a 2000 gm infant girl at 38 weeks gestation. Apgar scores are 6 and 8 at 1 and 5 minutes after delivery. The placenta weighs 400 gm. Which of the following statements is the most appropriate interpretation of these findings?

A study is performed of twin placentas. These placentas are examined grossly and microscopically following delivery. Most of these twin placentas are found to be diamnionic and dichorionic upon microscopic examination of dividing membranes. Which of the following is most likely to be found with increased frequency in infants with such placentas?

A 2-year-old child has failure to thrive. The child exhibits convulsions. On physical examination there is hepatomegaly along with multiple ecchymoses of various ages of the skin. Laboratory studies show a blood glucose of 31 mg/dL. Liver biopsy us performed and microscopic examination shows hepatocytes filled with clear vacuoles that stain positively for glycogen. Which of the following inborn errors of metabolism is this child most likely to have?

A 10-year-old boy is mentally retarded, but able to carry out activities of daily living, including feeding himself and dressing himself. On physical examination, he has brachycephaly and oblique palpebral fissures with prominent epicanthal folds. On the palm of each hand is seen a transverse crease. Upon auscultation of the chest, there is a loud systolic murmur. Which of the following diseases will he most likely develop by the age of 20?