Primary pulmonary angiosarcoma: A case report.

Primary sarcoma is uncommon in the lung, and primary angiosarcoma is exceedingly rare. We report a case of primary pulmonary angiosarcoma of the left lung with emphasis on its growth pattern in the lung. A 48-year-old Japanese man was admitted to our hospital because of dyspnea on exertion. He was subsequently found to have left pleural effusion. Computed tomography shows a nodular lesion measuring 7 × 4 cm in his left lung. Obstruction of the left inferior lobar bronchus was observed, and endobronchial biopsy suggested angiosarcoma. Left pneumonectomy was performed. On macroscopic examination of the cut surface, multiple nodular lesions were observed particularly in portions around branches of pulmonary artery along bronchioles. Histological examination revealed vascular channel-like structure with vague lumen formations by atypical polygonal or spindle-shaped neoplastic cells. Immunohistochemically, the neoplastic cells are positive for FLI-1, ERG, CD31 and von Willebrand factor/factor VIII-related antigen, but not CD34. Angiosarcoma is a particularly rare form of primary pulmonary tumors, and this case report describes its unique macroscopic growth pattern in the lung.