Which of the following is least likely cause of hemoptysis

Answer is B (Empyema): Empyema by itself is not a cause for hemoptysis. Pneumonia, Mitral stenosis and Bronchiectasis are established causess for hemoptysis. Differential Diagnosis of hemoptysis Tracheobronchial source Neoplasm (branchogenic carcinoma, endobronchial metastatic tumor, Kaposi's sarcoma, bronchial carcinoid) Bronchitis (acute or chronic) Bronchiectasis Broncholithiasis Airway trauma Foreign body Pulmonary parenchymal source Lung abscess Pneumonia Tuberculosis Mycetoma ("fungus ball") Goodpasture's syndrome Idiopathic pulmonary hemosiderosis Wegener's granulomatosis Lupus pneumonitis Lung contusion Primary vascular source Aerivenous malformation Pulmonary embolism Elevated pulmonary venous pressure (esp. mitral stenosis) Pulmonary aery rupture secondary to balloon- tip pulmonary aery catheter manipulation Miscellaneous/rare causes Pulmonary endometriosis (catamenial hemoptysis) Systemic coagulopathy or use of anticoagulants or thrombolytic agents