[Primary left atrial myxofibrosarcoma; report of a case].

We herein report a very rare case of a primary left atrial myxofibrosarcoma. A 61-year-old female presented with dyspnea and a wet cough. Chest X-ray film showed cardiomegaly and pulmonary congestion. Echocardiography and computed tomography revealed a left atrial tumor obstructing blood flow to the left ventricle. She was diagnosed with acute congestive heart failure due to functional mitralstenosis secondary to a left atrial tumor, and an emergency operation was performed. The tumor, which occupied left atrium, attached to the posterior wall of the left atrium and to the mitral valve, but had not invaded the left atrial wall. The tumor was removed from the left atrial wall, preserving the mitral valve and valve leaflets. The patient's post operative course was uneventful. The pathological diagnosis was myxofibrosarcoma, which rarely develops in the heart.