Intravenous leiomyomatosis: CT findings.

Intravenous leiomyomatosis (IVL) is a rare smooth muscle tumor. Although IVL is histologically benign, it might be aggressive in its behavior and can grow into pelvic veins and the inferior vena cava (IVC) extending into the heart chambers and pulmonary vasculature. Occasionally, it was found to have lung metastasis. We describe four cases of IVL in the IVC with a history of hysterectomy for uterine leiomyoma, one extending into the left renal vein and three growing into the right heart chamber. We report the computed tomography (CT) findings in the four cases and briefly discuss the CT features of IVL in order to help making accurately preoperative diagnosis and improve the rate of surgical resection and survival.