Inferior vena cava obstruction by a cardiac mass: unusual presentation of primary antiphospholipid syndrome.

We present a previously healthy 43-year-old woman with a cardiac mass that caused almost total occlusion of the inferior vena cava at its junction with the right atrium. The resected mass proved to be a thrombus. Preoperative imaging tests could not distinguish it from other intracardiac tumors such as myxoma. A postoperative immunological study revealed a primary antiphospholipid syndrome. This case presents an unusual diagnosis of antiphospholipid syndrome and a rare location of a cardiac thrombus.