Intracardiac extension of intravenous leiomyomatosis.

A 42-year-old woman was found to have intravenous leiomyomatosis of the uterus with extension into the inferior vena cava and right atrium. Intravenous leiomyomatosis is a rare neoplastic disease characterized by invasion of venous channels by a benign smooth muscle tumor arising either from the wall of a vessel or from a uterine myoma. Intracardiac extension is often initially misdiagnosed as a right atrial myxoma and may cause death by mechanical obstruction. The diagnosis of intravenous leiomyomatosis should be considered in young women with cardiac symptoms associated with a right atrial mass who also have a pelvic mass or who have previously undergone hysterectomy because of leiomyoma uteri.