[Left atrial sarcoma with the initial diagnosis of myxoma]

Primary tumors of the heart are rare. The majority of these tumors are benign, with myxomas located in the left atrium being the most common form. Almost all malignant tumors are sarcomas and occur preferentially in the right side of the heart. The case of a 73-year-old woman who presented with symptoms of mitral valve stenosis is reported. Echocardiography revealed a left atrial mass that was interpreted as atrial myxoma. At the operation, the tumor which was lobulated and had a smooth surface was arising from posterior wall of left atrium extending into the mitral annulus. Wide surgical excision was possible with left atrial reconstruction and mitral valve replacement. Histological and immunohistochemical studies revealed malignant undifferentiated sarcoma extending to the surface of mitral valve. Postoperative metastatic work-up showed no evidence of dissemination. The patient survived the operation without adjuvant radiation and chemotherapy and has been symptom-free over 1 year. At present, 16 months following the operation, the patient is alive with no evidence of disease.