Abstract
A 65-year-old man with dyspnea and hemoptysis presented with a right upper lobe mass associated with enlarged mediastinal lymph nodes and bilateral pulmonary nodules on chest computed tomography (CT), suspected lung cancer. Bronchial and CT-guided biopsies revealed poorly differentiated carcinoma. His condition deteriorated rapidly before a definitive diagnosis could be made. Autopsy revealed primary mediastinal choriocarcinoma. Primary mediastinal choriocarcinomas are rare, difficult to diagnose early and have a poor prognosis. In patients with a tumor expanding across the lung and mediastinum and exhibiting pathologic findings of a pooly differentiated carcinoma, we should consider choriocarcinoma, evaluating the serum β-human chorionic gonadotropin levels.