Lung Carcinoma Origin: mostly bronchial epithelium the most frequently diagnosed cancer in the world the most common cause of cancer mortality worldwide Ages: 40-70 y, males > females Epidemiology: ETIOLOGIES: Tobacco Smoking Industrial hazards and air pollution Molecular genetics Histogenesis: Bronchial columnar epithelium→metaplasia→dysplasia→Squamous cell carcinoma Bronchial columnar epithelium and glandular epithelium→Adenocarcinoma Clara cell → bronchioloalveolar carcinoma Type II pneumocytes Neuroendocrine argentaffin (Kulchitsky) cells → Small cell lung carcinoma neuroendocrine cells (unclear) → Large cell lung carcinoma Morphology: Grossly Central (bronchogenic) carcinoma Peripheral carcinoma Diffuse type (rare) https://ww...