title: Nerve sheath tumors involving the sacrum. Case report and classification scheme.
abstract: Nerve sheath tumors that involve the sacrum are rare. Delayed presentation is common because of their slow-growing nature, the permissive surrounding anatomical environment, and nonspecific symptoms. Consequently, these tumors are usually of considerable size at the time of diagnosis. The authors discuss a case of a sacral nerve sheath tumor. They also propose a classification scheme for these tumors based on their location with respect to the sacrum into three types (Types I-III). Type I tumors are confined to the sacrum; Type II originate within the sacrum but then locally metastasize through the anterior and posterior sacral walls into the presacral and subcutaneous spaces, respectively; and Type III are located primarily in the presacral/retroperitoneal area. The overwhelming majority of sacral nerve sheath tumors are schwannomas. Neurofibromas and malignant nerve sheath tumors are exceedingly rare. Regardless of their histological features, the goal of treatment is complete excision. Adjuvant radiotherapy may be used in patients in whom resection was subtotal. Approaches to the sacrum can generally be classified as anterior or posterior. Type I tumors may be resected via a posterior approach alone, Type III may require an anterior approach, and Type II tumors usually require combined anterior-posterior surgery.
authors.affiliation: Department of Neurosurgery, University of Utah, Salt Lake City, Utah 84132-2303, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Klimo
authors.forename: Ganesh
authors.initials: G
authors.lastname: Rao
authors.forename: Richard H
authors.initials: RH
authors.lastname: Schmidt
authors.forename: Meic H
authors.initials: MH
authors.lastname: Schmidt
mesh_terms: D000063:Accidents, Traffic; D000328:Adult; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D033162:Incidental Findings; D017116:Low Back Pain / Q000209:etiology; D008279:Magnetic Resonance Imaging; D016343:Monitoring, Intraoperative; D009104:Multiple Trauma / Q000175:diagnosis; D009442:Neurilemmoma / Q000145:classification / Q000150:complications / Q000175:diagnosis / Q000601:surgery*; D009455:Neurofibroma / Q000175:diagnosis; D010014:Osteolysis / Q000209:etiology; D012186:Retroperitoneal Neoplasms / Q000145:classification / Q000150:complications / Q000175:diagnosis / Q000601:surgery*; D012447:Sacrum / Q000469:parasitology; D001750:Urinary Bladder, Neurogenic / Q000175:diagnosis; D014549:Urinary Incontinence / Q000209:etiology