Retroperitoneal leiomyosarcoma mimicking an ovarian tumor diagnosed using a negative ovarian pedicle sign.

Retroperitoneal leiomyosarcoma (RPLMS) is rare and usually presents as a large abdominal mass with poor clinical symptoms. Radiological findings of an RPLMS arising in the pelvis of a woman resemble those of adnexal tumors. Herein, we present a case of RPLMS mimicking an adnexal tumor which was differentiated from having an ovarian origin as the right ovarian vein was passing through the tumor but there was no direct vascular connection with the tumor. Therefore, it is important to identify the ovarian vein to distinguish between these tumors.