[Sarcoma of the pulmonary artery].

Two cases of pulmonary artery angiosarcomas are reported. Pulmonary artery tumor was diagnosed during exploratory thoracotomy in the first case. It was suspected on magnetic resonance imaging and confirmed by surgery in the second case. The therapeutic was a right pneumonectomy for the first patient and a tumor resection followed by chemotherapy and radiotherapy on cerebral metastases for the second patient. Both our patients died, 13 and 44 months after surgery. On the basis of histological and immunohistochemical findings both tumors were angiosarcomas. Ultrastructural examination in the second case revealed an endothelial differentiation. The review of 142 previously reported cases of pulmonary artery sarcomas and these ultrastructural findings suggest that pulmonary artery sarcomas may have multiple origins; leiomyosarcomas deriving from arterial smooth muscle; angiosarcomas deriving from the endothelium and undifferentiated sarcomas or "myointimal sarcomas" deriving from myointimal cells.