Combined diagnostic imaging for retroperitoneal schwannoma.

Retroperitoneal tumors are occasionally encountered by gynecologists, and differential diagnosis from adnexal tumors is important, however, it is difficult in many cases. We report a case in which we preoperatively diagnosed a benign solid tumor in the retroperitoneum of the pelvic cavity on the basis of a variety of diagnostic images, including FDG-PET. Postoperative histological examination showed a benign schwannoma in the pelvis. We discuss the usefulness of FDG-PET combined with MRI and other diagnostic images as a means of differentiating between the characteristics of retroperitoneal tumors.