[Hemoptysis caused by bleeding into a bleb].

A man in his 40s was admitted to our hospital for hemoptysis. A chest computed tomography showed a mediastinal mass adjacent to the left side wall of the ascending aorta with infiltrative shadows of the left upper lobe. In spite of medical treatment, hemoptysis continued, and the surgery was performed. The thoracoscopic findings showed hematoma in the bullous cavity. Partial resection of the left upper lobe was performed. Histopathological findings in the resected specimen revealed a bleb that was filled with blood.