A retroperitoneal femoral nerve schwannoma as a cause of chronic pelvic pain.

This is a case report of pelvic pain caused by a large retroperitoneal femoral nerve schwannoma. A 31-year-old woman, gravida 2 para 2, was referred for surgical treatment of her chronic right lower quadrant pain. Laparoscopy revealed normal pelvic anatomy and a 7- x 5-cm mass overlying the right psoas muscle and involving the right femoral nerve. A combination of laparoscopic and laparotomy dissection allowed complete excision of the mass. Pathological analysis of the mass revealed a benign schwannoma of the femoral nerve sheath. Transient right femoral neuropathy complicated her postoperative course. Nongynecologic causes of pelvic pain are common and may include neurologically derived causes. Retroperitoneal schwannomas are uncommon and occur in about 0.5% of schwannomas. Complete surgical excision is recommended and results in an excellent cure rate.