摘要

The incidence of primary cardiac tumors is extremely low, ranging from 0.0017% to 0.019%.(1) Primary tumors can be categorized into benign or malignant tumors, in which 75% of primary tumors are benign with myxomas comprising 50% of the cases. On the other hand, malignant tumors constitute less than 25% of primary cardiac neoplasms and are manifested predominantly as sarcoma in various forms. The clinical(2) manifestations of cardiac tumors are protean, as they are dependent upon the location and the severity of obstruction or compression of valvular orifice and cardiac cavity. Therefore it is often difficult to reach the precise diagnosis prior to surgery. Although most tumors found arising from the interatrial septum and expanding into the left atrium are benign myxomas,(3) an effort should be made towards a preoperative differential diagnosis. Here we reported a case of a left atrial, undifferentiated sarcoma mimicking left atrial myxoma.