The great masquerade: Empyema thoracis as an unusual presentation of primary lung malignancy.

Primary lung malignancy presenting as empyema is rare, with a reported incidence of 0.3%. We report a case of a 60- year-old man presenting with unilateral pleural effusion; diagnostic thoracocentesis confirmed Salmonella empyema. Post-drainage, chest radiograph showed persisting right hemithorax opacity; subsequent computed tomography revealed a right lung mass with right upper lobe bronchus obliteration. Percutaneous biopsy confirmed advanced stage lung adenocarcinoma. We discuss the mechanism of post-obstructive pneumonia in lung cancerassociated empyema and the utility of bedside ultrasound in diagnosis of lung masses. Clinicians are alerted to the possibility of lung malignancy in elderly patients presenting with empyema.