Malignant fibrous histiocytoma of the heart.

A 33-year-old woman presented signs and symptoms which suggested mitral stenosis and insufficiency. Subsequent echocardiographic and angiographic testing demonstrated a left atrial tumor which was suspected clinically to be a left atrial myxoma. At surgery, the tumor was partially resected and histological examination revealed that the mass to be a malignant fibrous histiocytoma. At autopsy, the tumor was found to be localized in the heart, and there was no metastasis.