Benign retroperitoneal schwannoma: a case series and review of the literature.

To present our experience with four retroperitoneal schwannomas treated by surgical excision and review the current literature. Retroperitoneal schwannomas are rare, benign tumors and infrequently present to the urologist. From 1997 through 2002, the charts of 164 patients with a diagnosis of benign retroperitoneal soft tissue mass were reviewed. Of those, four had a pathologic diagnosis of retroperitoneal schwannoma. Three of the 4 patients were women, with a median age of 54 years (range 46 to 80). The average tumor size was 13.7 cm (range 8.8 to 20). All patients underwent magnetic resonance imaging, computed tomography, or ultrasonography, and 3 of the 4 patients underwent a computed tomography-guided fine needle aspiration biopsy (all were either inaccurate or inconclusive). All patients underwent complete tumor excision with free margins of resection and tolerated surgery without any complications. None of the patients have had any evidence of recurrence at a mean follow-up of 26 months (range 10 to 48). Retroperitoneal schwannomas are difficult to diagnose preoperatively. Computed tomography-guided fine needle aspiration biopsy does not appear to provide an accurate preoperative diagnosis. The surgical approach should focus on complete excision of the mass. Patients undergoing complete surgical resection tend to do well without evidence of early recurrence.