Segments of lung?
- 1. Apical
- 2. Posterior
- 3. Anterior
- 4. Lateral
- 5. Medial
- 6. Superior
- 7. Medial Basal *
- 8. Anterior Basal
- 9. Lateral Basal
- 10. Posterior Basal
- * Medial basal (7) not present in left lung
- [@ A PALM Seed Makes Another Little Palm,
- Remember - 2 sets of pyramids
- - (apical, anterior, posterior, medial, lateral) and
- - (superior, anterior, posterior, medial and lateral)]
Etiology of lung cancer?
- Cigarette smoking - most important risk factor
- Radon gas exposure- second most important risk factor. Radon is a natural radioactive gas released from the normal decay of uranium in the soil.
- Asbestos, arsenic, chromium, nickel, organic chemicals
- Iatrogenic radiation exposure,
- Air pollution, and
- Secondary smoke from nonsmokers.
Smoking and lung cancer?
- - Most important risk factor for lung cancer
- - Two lung cancer types—Squamous cell and Small cell carcinoma—are extraordinarily rare in the absence of cigarette Smoking.
- - Approximately 25% of all lung cancers worldwide and 53% of cancers in women are not related to smoking, and most of them (62%) are adenocarcinomas.
Pathological classification of lung cancer?
- A. Non–small cell lung carcinoma
- - Large cell
- - Squamous cell - most common cancer in men
- - Adenocarcinoma (30%) - The incidence of adenocarcinoma has increased over the last several decades, and it is now the most common lung cancer
- B. Neuroendocrine tumors.
- - Carcinoids
- - Small cell lung carcinoma
Signs and symptoms of lung cancer?
2. Nonpulmonary Thoracic Symptoms -
- 1. Pulmonary Symptoms
- Cough (secondary to irritation or compression of a bronchus)
- Dyspnea (usually due to central airway obstruction or compression, with or without atelectasis)
- Wheezing (with narrowing of a central airway of >50%)
- Hemoptysis (typically, blood streaking of mucus that is rarely massive; indicates a central airway location),
- Pneumonia (usually due to airway obstruction by the tumor), and
- Lung abscess (due to necrosis and cavitation, with subsequent infection).
result from invasion of the primary tumor directly into a contiguous structure (e.g., chest wall, diaphragm, pericardium, phrenic nerve, recurrent laryngeal nerve, superior vena cava, and esophagus), or from mechanical compression of a structure (e.g., esophagus or superior vena cava) by enlarged tumor-bearing lymph nodes.
- Three types of symptoms, depending on the extent of chest wall involvement, are possible:
- (a) pleuritic pain, from noninvasive contact of the parietal pleura with inflammatory irritation or direct parietal pleural invasion;
- (b) localized chest wall pain, from deeper invasion and involvement of the rib and/or intercostal muscles; and
- (c) radicular pain, from involvement of the intercostal nerve(s). Radicular pain may be mistaken for renal colic in the case of tumors invading the inferoposterior chest wall.
3. Associated Paraneoplastic Syndromes -
4. Symptoms Associated with Metastatic Lung Cancer
- Other specific nonpulmonary thoracic symptoms include
- 1. Pancoast’s syndrome
- 2. Phrenic nerve palsy
- 3. Recurrent laryngeal nerve palsy
- 4. Superior vena cava (SVC) syndrome
- 5. Pericardial tamponade
- 6. Back pain
- 7. Dysphagia is usually secondary to external esophageal compression by enlarged lymph nodes.
- Lung cancer metastasizes most commonly to the CNS, vertebral bodies, bone, liver, adrenal glands, lungs, skin, and soft tissues.
Paraneoplastic Syndromes associated with lung cancer?
- 1. Hypertrophic pulmonary osteoarthropathy (HPO) - Clinically, ankle, feet, forearm, and hand tenderness and swelling are characteristic, resulting from periostitis of the fibula, tibia, radius, metacarpals, and metatarsals. Clubbing of the digits may occur
- 2. Hypercalcemia - due to ectopic parathyroid hormone secretion
- 3. Hyponatremia - from the inappropriate secretion of antidiuretic hormone from the tumor
- 4. Cushing’s syndrome - Autonomous tumor production of ACTH-like molecule
- 5. Peripheral and central neuropathies -
- 6. Lambert-Eaton syndrome
Short note on Pancoast tumor. [TU 2064/5]
The superior sulcus refers to an apical pleuro-pulmonary groove formed by the subclavian artery as it curves in front of the pleura runs upward and lateral immediately below the apex.
Any tumor of the superior sulcus, including tumors without evidence for involvement of the neurovascular bundle, is now commonly known as Pancoast’s tumors. The designation is reserved for tumors involving the parietal pleura or deeper structures overlying the first rib. Chest wall involvement at or below the second rib is not a Pancoast’s tumor.
Clinical features of Pancoast's tumor include -
- - apical chest wall and/or shoulder pain (from involvement of the first rib and chest wall);
- - Horner’s syndrome (Stellete Sympathetic chain involvement, Anhidrosis, Miosis, Ptosis, Loss of ciliospinal reflex, Enophathlomus) [@ SAMPLE] and
- - radicular arm pain (from invasion of T1, and occasionally C8, brachial plexus nerve roots).
Discuss the diagnostic difficulties in bronchogenic carcinoma. [TU 2056]
Investigations for lung cancer?
- CECT chest
- MRI - reserved for those with contrast allergies or with suspected mediastinal, vascular, or vertebral body invasion.
- Bronchoscopy and tissue diagnosis
- PET scan - to evaluate metastasis
Biospy modalities for lung carcinoma?
- Bronchoscopy and tissue diagnosis - can be obtained by one of four methods:
- 1. Brushings and washings for cytology
- 2. Direct forceps biopsy of a visualized lesion
- 3. Endobronchial ultrasound-guided fine-needle aspiration (FNA) of an externally compressing lesion without visualized endobronchial tumor
- 4. Transbronchial biopsy with fluoroscopy to guide forceps to the lesion or electromagnetic navigational bronchoscopy.
- Video-assisted thoracoscopic biopsy
- Thoracotomy and biopsy - for deep seated lesions
Tissue diagnosis in central and peripheral lesions?
For peripheral lesions (roughly the outer half of the lung) - transbronchial biopsy followed by brushings and washings.
- For central lesions
- - direct forceps biopsy for visible lesions
- - endobronchial ultrasound (EBUS) for no visible endobronchial lesions
TNM staging of lung cancer?
- T1 -Tumor ≤3 cm
- • T1a—Tumor ≤2 cm
- • T1b—Tumor 2-3 cm
- T2 - 3-7 cm
- - Involves main bronchus ≥2cm, distal to carina
- - Invades visceral pleura
- - Associated with atelectasis or obstructive pneumonitis that extends to the hilar region
- • T2a—Tumor 3-5 cm
- • T2b—Tumor 5-7 cm
- • Tumor >7 cm or one that directly invades any of the following: chest wall (including superior sulcus tumors), diaphragm, phrenic nerve, mediastinal pleura, parietal pericardium; or
- • Tumor in the main bronchus <2 cm distal to the carina but without involvement of the carina or
- • Associated atelectasis or obstructive pneumonitis of the entire lung
- Tumor of any size that invades any of the following: mediastinum, heart, great vessels, trachea, recurrent laryngeal nerve, esophagus, vertebral body, carina
- N1 Metastasis in ipsilateral peribronchial and/or ipsilateral hilar lymph nodes and intrapulmonary nodes
- N2 Metastasis in ipsilateral mediastinal and/or subcarinal lymph node(s)
- N3 Metastasis in contralateral mediastinal, contralateral hilar, ipsilateral or contralateral scalene, or supraclavicular lymph node(s)
M1 Distant metastasis
Treatment of Small Cell Lung Carcinoma?
Isolated lung lesion (absence of N2 disease)- lobectomy followed by chemotherapy
More advanced-stage disease - no benefit from surgical resection ; treatment is chemotherapy with or without radiation therapy
Staging of lung cancer?
- Stage I and II
- - T1 and T2 tumors (with or without N1 involvement)
- - T3 tumors (without N1 involvement)
- Stage III (locally advanced tumors)
- - All T4 disease
- - T3N1 disease
- - All N2 disease
Stage IV - metastatic disease
Outline the different modalities of management of bronchogenic carcinoma. [TU 2056]
Treatment for lung cancer can be roughly grouped into three major categories,as follows:
- 1. Stage I and II tumors
- - may be completely resected with surgery.
- - Surgical resection, lobectomy or pneumonectomy depending on the tumor location.
- - Sleeve resection is performed for tumors located at airway bifurcations when an adequate bronchial margin cannot be obtained by standard lobectomy.
- - Treatment options for high risk patients or nonoperable patient
- a) Limited resection (segmentectomy or wedge resection).
- b) Tumor ablation techniques - radiofrequency ablation and stereotactic body radiotherapy
- 3. Locally advanced tumors (Stage III)
- - may be mechanically removed with surgery; however, surgery does not consistently control the micrometastases that exist within the general area of the operation or systemically.
- - Surgical resection is appropriate for patients with a single-station metastasis with a single lymph node < 3 cm.
- - When N2 nodes are found intraoperatively - it is acceptable to either proceed with anatomic resection and mediastinal lymph node sampling/dissection or to stop the procedure, refer the patient for induction therapy, and re-evaluate for resection after induction therapy is completed.
- - When histologically confirmed metastases are found during preoperative staging evaluation, patients should be referred for induction chemotherapy
- 2. Stage IV disease
- - not typically treated by surgery except in patients requiring surgical palliation.
- - Combination chemotherapy with platinum doublets (paclitaxel and carboplatin)
- - The addition of bevacizumab to paclitaxel and carboplatin improve survival.
Role of histological diagnosis in management of lung cancer?
- Treatment with pemetrexed or bevacizumab-based chemotherapy is associated with improved progression-free survival in patients with adenocarcinoma but not squamous cell cancer.
- Life-threatening hemorrhage has occurred in patients with squamous cell carcinoma who were treated with bevacizumab.
- EGFR tumor kinase inhibitors are now recommended as first-line therapy in advanced adenocarcinoma.
Discuss the predisposing factors that increase the chances of complication in thoracic surgery. [TU 2062/5]
Thoracic outlet syndrome
Page 1603, Sabiston
Causes of thoracic outlet syndrome?
Congenital abnormalities - cervical rib, prolonged transverse process, and muscular abnormalities (e.g., in the scalenus anterior muscle, a sickle-shaped scalenus medius) or fibrous connective tissue anomalies.
Trauma (e.g., whiplash injuries) or repetitive strain is frequently implicated.
Rarer acquired causes include tumors, hyperostosis, and osteomyelitis.