[A case of pulmonary sarcoma with a differential diagnosis from preoperative pulmonary thromboembolism].

Primary sarcoma of pulmonary artery is a rare tumor. A 46-year-old man was hospitalized because of dyspnea and hemoptysis. Pulmonary thromboembolism was suspected by chest X-ray, scintigraphy, and CT. But the mass had a to-and-fro movement above the pulmonary valve on pulmonary arterial cineangiography. We strongly suspected that it was primary neoplasm of pulmonary artery. The pulmonary artery was opened under cardiopulmonary bypass. The tumor arised pulmonary trunk and extended peripherally. The tumor was surgically removed as complete as possible, though a proxymal balloon embolectomy was unsuccessful. The histological finding was malignant fibrous histiocytoma of the pulmonary artery.