Three-dimensional CT vascular mapping of a juxtauterine pelvic schwannoma suggesting retroperitoneal origin: a case report.

Pelvic masses adjacent to the uterus can be difficult to distinguish from uterine leiomyomas on magnetic resonance imaging (MRI), and accurate estimation of the organ of origin is important for surgical planning. A 54-year-old perimenopausal woman (gravida 3, para 2) was referred for evaluation of a pelvic mass detected during a routine health checkup. Pelvic examination and transvaginal ultrasonography revealed an 11.3 cm mass on the left side of the uterus. MRI demonstrated a well-circumscribed 10 cm mass broadly abutting the left lateral cervical wall, suggestive of a degenerated leiomyoma; however, the organ of origin could not be determined. Contrast-enhanced computed tomography (CT) with three-dimensional reconstruction demonstrated that the tumor was supplied by two direct branches from the internal iliac artery, without apparent feeding vessels from the uterine artery, suggesting a retroperitoneal origin. Tumor resection with total hysterectomy and bilateral salpingo-oophorectomy was performed. The feeding arteries identified preoperatively were confirmed and managed intraoperatively. Histopathological examination determined that the tumor was a schwannoma. The postoperative course was uneventful, and the patient was discharged on postoperative day 6. This case suggests that three-dimensional vascular mapping using contrast-enhanced CT may aid in estimating the organ of origin and facilitate individualized surgical planning for pelvic masses adjacent to the uterus.