Bronchogenic Carcinoma(Lung Cancer)Respiratory departmentDefinitionlBronchogenic carcinoma refers to the malignant tumor which grows in the bronchus.Originating from mucus or gland of bronchus.Incidence and mortalitylBronchogenic carcinoma has increased remarkable in incidence and mortality during half of the century and has become the most frequent visceral malignant diseases of men.The mortality of lung cancer hold the first place among all kinds carcinomas.EtiologylThe cause of lung cancer is