-
What are the clinical classification of tumors?
- behavior of tumor
- clinical presentation and outcome
-
What are the histological classification of tumors?
microscopic cell type
-
What is benign?
- Limited growth potential
- usually good outcome for patient
-
What is malignant?
- Uncontrollable growth
- eventually kills the patient
-
What are the different ways to compare benign and malignant tumors?
- Gross feature
- microscopic features
- cellular features
- biologic features
- metastasis
- danger
-
What do benign tumors look like?
sharply demarcated from surrounding tissue - clean sharp edges, well circumscribed, often encapsulated
-
Do benign tumors grow fast or slow?
Slow
-
What is the external surface of a benign tumor look like?
Smooth
-
Is necrosis and hemorrhage present in benign tumors?
No
-
What is the capsule like of a benign tumor?
connective tissue or adjacent normal tissue - which is compressed, atrophied, and fibrotic
-
Are malignant tumors well circumscribed?
No, not clearly separated from normal tissue
-
What is the growth pattern like of a malignant tumor?
- Infiltrative
- invades surrounding tissue
- like plant roots grow in soil
-
Is the growth rate of a malignant tumor fast or slow?
Fast
-
Do malignant tumors have capsules?
No
-
What is the external surface of malignant tumors like?
Irregular
-
Is necrosis and hemorrhaging present in malignant tumors?
yes
-
What does a benign tumor look like microscopically?
Composed of cells that resemble the tissue of origin
-
What does a malignant tumor look like microscopically?
- Composed of cells that can look different from tissue of origin
- undifferentiated
- anaplastic
-
What is anaplastic?
Loss of adult cell features primitive in type
-
What does the cytoplasm of benign tumors look like?
- Well developed
- uniform
- abundant
-
What does the nucleus of a benign tumor look like?
- Regular and uniform between cells
- relatively small nucleus
- chromatin regular and evenly distributed
- nucleolus is not prominent
- mitotic figures are absent or rare
-
What does the nucleus of a malignant tumor look like?
- vary in size and shape
- relatively large
- hyperchromatic - more chromatin than normal, uneven distribution
-
What does the nucleus look like of a malignant tumor?
- Nucleoli prominent, may be multiple
- mitotic figures - often present due to rapid rate of division
-
What does the cytoplasm of a malignant tumor look like?
- Variable a mount between cells
- Usually scant - not as much as normal
-
What does a benign tumor look like biologically?
May retain some of the complex functions of tissue of origin
-
What does a malignant tumor look like biologically?
- Too undifferentiated to function normally
- all cellular efforts directed to growth and mitosis
-
Do benign tumors metastasize?
No
-
Do malignant tumors metastasize?
Yes but not all malignant tumors metastasize
-
When can benign tumors be dangerous?
- Where they are located (example - in the skull)
- accidental complication (example - trauma, infection)
- production of excess hormone (insulinoma)
-
Define metastasis.
Spread of a tumor from its original site to another site in the body that is not adjacent to the original site
-
What are the three different ways a tumor can spread (metastasize)?
- Circulatory system
- lymphatic system
- implantation (seeding)
-
How do tumors spread through the circulatory system?
- Tumor cells carried by blood
- like to lodge in filtering sites, especially lungs
- radiograph lungs to look for metastatic tumors
-
How do tumors spread through the lymphatic system?
- Carried by lymph fluid
- metastasis to local lymph nodes
- may biopsy local lymph nodes
-
How do tumors spread through implantation?
- Occurs when a tumor invades the surface of an organ, tumor comes into contact with a body cavity
- cells break off original tumor
- carried by peritoneal or pleural fluid to new sites - new tumors
- abdominal tumors can cause ascites
-
How can surgery cause a tumor to metastasize?
- Excision not wide enough and leave some behind
- drag tumor cells through normal tissue with scalpel
-
What are the steps to metastasis?
- Tumor develops a mass of cells with ability to metastasize
- mass of cells expands and invades blood or lymph vessels or enters a body cavity
- cells break off mass
- carried by fluid to distant sites (blood, lymph, body fluid)
- survive, grow at new site (escape immune system, formation of new blood vessels to support tumor growth)
-
What are the names if benign tumors?
- "Oma" - lipoma, fibroma
- "adenoma" - glandular origin
-
What are the different names for malignant tumors?
-
What is the origin of sarcoma?
- derived from mesenchymal tissue
- connective tissue, blood and lymph vessels, skeletal and smooth muscle
-
What is the origin of carcinoma?
- epithelial tissue
- derived from fetal epithelium
-
What is epithelial tissue?
- covering of external and internal surfaces of the body
- skin, lining of GI tract, glands, endothelium - inner lining of blood and lymph vessels, lining of heart
-
What is a malignant tumor of glandular origin?
adenocarcinoma
-
Is there such a thing as an adenosarcoma?
no
-
What are the two exceptions to the rules of naming tumors?
- malignant melanoma
- lymphoma - malignant tumor of lymphoid cells
-
What are some other names of tumor types?
- blastoma
- polyps
- papillomas
- mixed tumors
- teratomas
- melanomas
- tumors of lymphocytes
-
What are blastomas?
- malignant tumors composed of embryonic cells
- retinoblastoma
- nephroblastomas
-
What are polyps?
- any growth of mass protruding from a mucous membrane
- usually normal tissue, may be benign tumor
-
What are some locations of polyps?
- mucous membranes
- nose
- ears
- mouth
- lungs
- uterus
- cervix
- intestines
- bladder
-
What are the two base types of polyps?
-
What is pedunculated?
attached by a thin stalk
-
What is sessile?
broad base
-
What are papillomas?
- the common wart
- benign epithelium
-
Where are locations of papillomas?
- protrude from surface of skin
- inner surface of urinary bladder, mouth, larynx
-
Which species are papillomas more common in?
cattle and humans
-
What are mixed tumors?
have both mesenchymal and epithelial components
-
What are teratomas?
- tumors derived from germ cells (testis, ovary)
- develop into different tissues, randomly mixed
-
Are teratomas benign or malignant?
can be either
-
Are teratomas common in animals?
no
-
What is melanoma?
tumors of melanocytes - in skin
-
Which animals is melanoma the most common in?
dogs and grey horses
-
What are amelanotic melanomas?
- too undifferentiated to produce melanin
- usually highly malignant
-
Which species is lymphoma the most common in?
-
What are the different names of "tumors of lymphocytes"?
- lymphosarcoma
- lymphoma
- leukemia
- leukosis
- lymphomatosis
-
Which organs are involved in lymphoma?
- may be many
- may be just in blood
- lymph nodes, thymus, spleen, intestines, liver
-
Lymphoma can be caused by a virus in which animals? What viruses cause lymphoma?
- cats, cattle, chickens
- FeLV
- bovine viral leukosis
- avian leukosis virus
- rous sarcoma virus
-
What is leukemia?
- abnormal malignant cells in circulating blood
- may occur in lymphoma
- may have other blood cells involved
|
|
