Bronchogenic Carcinoma is the most common malignancy in males, it accounts for 32% of all cancer deaths in men, 85% of patients die within 5 years. Causes and incidence of Bronchogenic carcinoma (no definite aetiology) • Male > female • Peak incidence occurs between ages 55 and 65 years. • Predisposing factors: • The major cause is tobacco use particularly cigarette smoking • 3,4 benzpyrine is the carcinogenic substance especially if combined with asbestos. • Air pollution (coal combustion, cadmium and radon). • Occupation inhaled substances e.g asbestos, nickel and arsenic. • Radiation e.g atomic bomb survivors, uranium miners. • Genetic mechanism e.g dominant oncogenes and loss of tumour suppressor genes. The risk is increased 40 times fold for man smoking two packs /d. for 20 years . Pathology 1- Central or hilar type in a main bronchus, it invades the mediastinum early 2- Peripheral in small bronchus, it invades pleura early 3- Pancoast tumour, it is apical and invades the thoracic inelt early. • Naked eye appearance : Fungating mass - Malignant ulcer - Infiltrative type • Microscopic: WHO classification Methods of Spread of Bronchogenic carcinoma • Direct : lung, pleura, mediastinum, brachial plexus, sympathetic chain and phrenic nerve. • Lymphatic spread : - Hilar & mediastinum, then cervical L.N. -Retrograde lymphatic ==> (lymphangitis carcinomatosa) ==> cor pulmonale • Haematogenous : Bones, liver, brain Bronchoalveolar cell carcinoma (Bronchiolar carcinoma) arising in the terminal bronchioloalveolar regions accounts for 1-2% of lung tumors. It may be a peripheral solitary nodule or diffuse nodular lesion. It occurs in men and women equally and usually not associated with smoking. It may be associated with expectoration of a large volumes of mucoid sputum. Source : Bronchogenic Carcinoma causes, pathology, classification and spread
