Left atrial myxosarcoma with previously detected intestinal metastasis.

Primary cardiac myxosarcoma is a rare disease; it is exceedingly rare for symptoms of systemic metastasis to precede diagnosis of the primary cardiac tumor. We describe the case of a previously healthy 60-year-old man with left atrial myxosarcoma, who had first presented with jejunal intussusception due to intestinal polyposis. Three months after resection of the jejunum, the patient experienced cerebral infarction and pulmonary edema. Further physical evaluation, which included echocardiography for the 1st time, revealed a mass in the left atrium that protruded through the mitral valve into the left ventricle. At emergency cardiac surgery, we found that the tumor involved multiple sites of the left atrium, the pulmonary veins, and the mitral anterior leaflet. Two months after surgery, the patient died of massive cerebral hemorrhage. Necropsy disclosed multiple recurrences of the cardiac myxosarcoma and widespread metastatic lesions. The intestinal polyps that had been resected originally were diagnosed, on retrospective histopathologic examination, as metastases of the myxosarcoma. In this unusual case, the metastatic lesions were the 1st clinical manifestations of a malignant cardiac tumor.