Intravenous leiomyomatosis with cardiac extension: successful surgical management and histopathologic study.

A case of intravenous leiomyomatosis with cardiac extension was treated successfully with a two-stage operation: resection of the intracardiac and intracaval mass for the first stage and total hysterectomy with bilateral salpingo-oophorectomy for the second. Tumors were located either within or in continuity to dilated uterine veins. A leiomyomatous protrusion of the wall of a small uterine vein was found in two remote sections. The involved veins were located alone in the layer of apparently normal uterine smooth muscles. The findings suggest that intravenous leiomyomatosis originates from the smooth-muscle component of uterine veins.