Primary myxofibrosarcoma of the left atrium: case report and review of the literature.

A 63-year-old woman with progressive dyspnea underwent transthoracic echocardiography and was found to have a large multilobed mass in the left atrium that was attached to lateral wall. On inspection during surgery, the tumor was found to infiltrate the posterior mitral annulus and leaflet. The patient underwent surgical resection of the tumor and mitral valve replacement.