[Primary cardiac synovial sarcoma--a case report].

We report a case of cardiac synovial sarcoma, a very rare primary tumor of the heart. The patient was a 29-year-old man with chief complaint of dyspnea. On echocardiography, a tumor 42 mm in diameter occupying the most space of the left atrium was found. The tumor was obstructed the opening of the mitral valve. He was diagnosed with heart failure due to disturbance of the pulmonary venous return and hemodynamic mitral valve stenosis, and underwent surgery. The tumor was a 5-cm sphere originating in the left atrial posterior wall, and was covered with a sheath and solid. The atrial posterior wall was covered with a peel that appeared to be tumor tissue, and this tissue expanded toward the openings of the pulmonary veins bilaterally and the posterior cusp of the mitral valve. The tumor was resected together with the posterior wall. On pathologic examination, the tumor was diagnosed as a synovial sarcoma. Since no other primary focus was found, this tumor was judged to be a primary sarcoma of the heart. The patient was discharged with elimination of symptoms. The sarcoma recurred after 4 months, and the patient underwent a second operation. The recurrent tumor began from the site of resection of the previous operation and expanded up to the inferior pulmonary veins bilaterally. A wide area of the left atrial wall including the tumor was resected, and he was discharged again. The sarcoma recurred again, and he died of progression of heart failure and aggravation of general conditions after 8 months from the first operation.