Vanishing intravenous leiomyomatosis after hysterectomy: Assessment of the need to perform complete resection.

Intravenous leiomyomatosis (IVL) is a rare smooth muscle tumor that may extend into extrauterine veins. A high IVL recurrence rate has been reported after hysterectomy. A 44-year-old woman underwent total hysterectomy as a result of uterine leiomyoma, and IVL within the left uterine vein was incidentally found during the surgery. A residual tumor within the right ovarian vein was detected on contrast-enhanced computed tomography (CT) two days postoperatively. The tumor was diagnosed as IVL because it showed contrast enhancement on preoperative magnetic resonance imaging by retrospective re-interpretation. However, the tumor completely disappeared on contrast-enhanced CT without any medical treatment five months postoperatively. This is the first report of spontaneous regression of IVL. Postsurgical imaging was important to determine the residual extrauterine extension of IVL when it was incidentally found during gynecologic surgery. A hysterectomy alone may be adequate in selected cases, but long-term follow-up imaging is strongly recommended in all cases.