Uterine intravenous leiomyomatosis a rather rare pathologic condition, and a total of 139 cases have appeared in the English literature. Although two proposals for the histologic origin, uterine lyomyoma itself and/or vascular smooth muscle, have been widely accepted, the precise histogenesis still remains unclear. The additional 140th case of intravenous leiomyomatosis is described, and a third postulation for the histogenesis is proposed.