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Pathology - Lung carcinoma
Definition • A malignant epithelial neoplasm originating in the lung.
Epidemiology • The most prevalent and lethal cancer, resulting in over 1 million fatalities per year.
Aetiology • As much as 90% of instances can be directly linked to smoking. Carcinogenesis • TP53 mutations are prevalent across all varieties of lung cancer. • Overexpression of HER2 and KRAS in adenocarcinomas. • Overexpression of EGFR and deletion of 3p in squamous cell carcinomas. • The inactivation of RB is nearly ubiquitous in small cell carcinomas.
Presentation• Symptoms associated with localized tumor growth encompass increasing dyspnea, cough, thoracic discomfort, dysphonia or voice loss, hemoptysis, weight reduction, and recurrent pneumonia. Metastases may result in abdominal pain, bone pain, and neurological problems. A minority of small cell carcinomas manifest with paraneoplastic syndromes or superior vena cava syndrome.
Macroscopy • A solid white/grey neoplastic tumor located within the lung. Yellow consolidation may be observed in the lung parenchyma distal to substantial proximal tumors as a result of obstructive pneumonia. Pleural puckering may be observed over peripheral tumors that have infiltrated the pleura. • Metastatic tumor deposits may be observed in hilar lymph nodes.
Histopathology
Adenocarcinoma is a malignant epithelial tumor characterized by glandular development and/or mucus secretion. Squamous cell carcinoma is a malignant epithelial tumor characterized by keratinization and/or intercellular bridges. Small cell carcinoma is a malignant epithelial neoplasm characterized by diminutive cells with minimal cytoplasm, poorly defined cell boundaries, finely granular chromatin, and the absence of nucleoli. The mitotic count is elevated, and necrosis is frequently widespread. Large cell carcinoma is an undifferentiated (non-small) cell carcinoma that exhibits no signs of squamous or glandular differentiation.
Prognosis: • Dismal, with 5-year survival rates ranging from 7% to 10% in the majority of countries.
TNM 7 pathological staging of lung carcinomas
Primary tumour (T)
T1a: tumour d 2cm in size, confi ned to the lung.
T1b: tumour > 2–3cm in size, confi ned to the lung.
T2: tumour 3–7cm in size; tumour of any size that involves the main
bronchus 2cm or more distal to the carina, invades visceral pleura,
causes partial atelectasis.
T3: tumour > 7cm in size; tumour of any size that invades the chest wall,
diaphragm, pericardium, mediastinal pleura, main bronchus <2cm distal< />pan>
to the carina, causes total atelectasis; multiple tumour nodules in same
lobe.
T4: tumour of any size that invades the mediastinum, heart, great vessels,
carina, trachea, oesophagus, vertebra; multiple tumour nodules in same
lung, but different lobes.
Regional lymph nodes (N)
N0: no regional lymph node metastasis.
N1: metastasis in ipsilateral peribronchial or hilar lymph nodes.
N2: metastasis in ipsilateral mediastinal or subcarinal lymph nodes.
N3: metastasis in contralateral mediastinal or hilar lymph nodes or any
scalene or supraclavicular lymph nodes
Definition • A malignant epithelial neoplasm originating in the lung.
Epidemiology • The most prevalent and lethal cancer, resulting in over 1 million fatalities per year.
Aetiology • As much as 90% of instances can be directly linked to smoking. Carcinogenesis • TP53 mutations are prevalent across all varieties of lung cancer. • Overexpression of HER2 and KRAS in adenocarcinomas. • Overexpression of EGFR and deletion of 3p in squamous cell carcinomas. • The inactivation of RB is nearly ubiquitous in small cell carcinomas.
Presentation• Symptoms associated with localized tumor growth encompass increasing dyspnea, cough, thoracic discomfort, dysphonia or voice loss, hemoptysis, weight reduction, and recurrent pneumonia. Metastases may result in abdominal pain, bone pain, and neurological problems. A minority of small cell carcinomas manifest with paraneoplastic syndromes or superior vena cava syndrome.
Macroscopy • A solid white/grey neoplastic tumor located within the lung. Yellow consolidation may be observed in the lung parenchyma distal to substantial proximal tumors as a result of obstructive pneumonia. Pleural puckering may be observed over peripheral tumors that have infiltrated the pleura. • Metastatic tumor deposits may be observed in hilar lymph nodes.
Histopathology
Adenocarcinoma is a malignant epithelial tumor characterized by glandular development and/or mucus secretion. Squamous cell carcinoma is a malignant epithelial tumor characterized by keratinization and/or intercellular bridges. Small cell carcinoma is a malignant epithelial neoplasm characterized by diminutive cells with minimal cytoplasm, poorly defined cell boundaries, finely granular chromatin, and the absence of nucleoli. The mitotic count is elevated, and necrosis is frequently widespread. Large cell carcinoma is an undifferentiated (non-small) cell carcinoma that exhibits no signs of squamous or glandular differentiation.
Prognosis: • Dismal, with 5-year survival rates ranging from 7% to 10% in the majority of countries.
TNM 7 pathological staging of lung carcinomas
Primary tumour (T)
T1a: tumour d 2cm in size, confi ned to the lung.
T1b: tumour > 2–3cm in size, confi ned to the lung.
T2: tumour 3–7cm in size; tumour of any size that involves the main
bronchus 2cm or more distal to the carina, invades visceral pleura,
causes partial atelectasis.
T3: tumour > 7cm in size; tumour of any size that invades the chest wall,
diaphragm, pericardium, mediastinal pleura, main bronchus <2cm distal< />pan>
to the carina, causes total atelectasis; multiple tumour nodules in same
lobe.
T4: tumour of any size that invades the mediastinum, heart, great vessels,
carina, trachea, oesophagus, vertebra; multiple tumour nodules in same
lung, but different lobes.
Regional lymph nodes (N)
N0: no regional lymph node metastasis.
N1: metastasis in ipsilateral peribronchial or hilar lymph nodes.
N2: metastasis in ipsilateral mediastinal or subcarinal lymph nodes.
N3: metastasis in contralateral mediastinal or hilar lymph nodes or any
scalene or supraclavicular lymph nodes
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