Retroperitoneal neural sheath tumors: Cleveland Clinic experience.

Retroperitoneal neural sheath tumors are a rare clinical entity with a variable and nonspecific presentation, whose accurate preoperative diagnosis often can be difficult. Since July 1984, 9 retroperitoneal neural sheath tumors, including 3 benign schwannomas, 3 malignant schwannomas and 3 neurofibromas, were evaluated at our institution. Preoperative evaluation included a computerized tomography scan in all patients and magnetic resonance imaging in 4. Magnetic resonance imaging offered better resolution and anatomical definition in certain cases. Preoperative computerized tomography-guided needle biopsy, performed in 3 patients, yielded inaccurate or inconclusive results. The 6 patients with surgically resected benign schwannomas and neurofibromas had no local recurrences and all 6 had no evidence of disease (mean followup 17.3 and 14 months, respectively). Malignant tumors, especially when associated with von Recklinghausen's disease, offered a poor prognosis. Surgical considerations include complete tumor excision with free margins of resection and proper pathological evaluation to determine biological potential.