Intradural nerve sheath tumors
- Mark Bilsky, MD
Mark Bilsky, MD
- Attending Neurologic Surgeon
- Memorial Sloan-Kettering Cancer Center
- Professor Neurologic Surgery
- Weill Medical College of Cornell University
- Section Editors
- Robert Maki, MD, PhD
Robert Maki, MD, PhD
- Section Editor — Bone and Soft Tissue Tumors
- Professor of Medicine and Pediatrics
- Mount Sinai School of Medicine
- Jay S Loeffler, MD
Jay S Loeffler, MD
- Section Editor — Neurooncology
- Professor of Radiation Oncology
- Harvard Medical School
- Patrick Y Wen, MD
Patrick Y Wen, MD
- Section Editor — Neurooncology
- Professor of Neurology
- Harvard Medical School
- Alberto S Pappo, MD
Alberto S Pappo, MD
- Section Editor — Pediatric Oncology
- Head of Solid Malignancies Program
- St. Jude Children's Research Hospital
Spinal tumors are classified as extradural, intradural and extramedullary, or intradural intramedullary based upon their anatomic location. Nerve sheath tumors (NSTs) constitute about 25 percent of tumors arising in the intradural extramedullary space [1,2].
Although the majority of NSTs are confined to the intradural extramedullary space, some of these tumors extend into either the extradural compartment or the spinal cord. In addition, occasional spinal NSTs are confined to either the extradural or intramedullary spaces .
NSTs are derived from the Schwann cells and perineurial cells of the peripheral nervous system. Approximately 65 percent of intradural nerve sheath tumors are schwannomas, and most of the remainder are neurofibromas . Malignant NSTs are rare, constituting about 5 percent of such tumors.
The clinical presentation, diagnosis, and treatment of NSTs will be reviewed here. Peripheral extradural nerve sheath tumors, intramedullary spinal tumors, and meningiomas of the spinal cord are discussed separately. (See "Spinal cord tumors", section on 'Intramedullary tumors' and "Spinal cord tumors", section on 'Meningioma' and "Clinical presentation, histopathology, diagnostic evaluation, and staging of soft tissue sarcoma", section on 'Introduction'.)
EPIDEMIOLOGY AND ETIOLOGY
Intradural, extramedullary nerve sheath tumors (NSTs) may be either sporadic or associated with an inherited disorder. Sporadic NSTs are most common in the fifth to seventh decades and have a similar incidence in men and women . In addition, spinal NSTs are a manifestation of neurofibromatosis type 1 (NF1), neurofibromatosis type 2 (NF2), and schwannomatosis:
- Levy WJ, Latchaw J, Hahn JF, et al. Spinal neurofibromas: a report of 66 cases and a comparison with meningiomas. Neurosurgery 1986; 18:331.
- Nittner K. Spinal meningiomas, neurinomas and neurofibromas, and hourglass tumours. In: Handbook of Clinical Neurology, Vinken PH, Bruyn GW (Eds), Elsevier, New York 1976. p.177.
- Klekamp J, Samii M. Surgery of spinal nerve sheath tumors with special reference to neurofibromatosis. Neurosurgery 1998; 42:279.
- el-Mahdy W, Kane PJ, Powell MP, Crockard HA. Spinal intradural tumours: Part I--Extramedullary. Br J Neurosurg 1999; 13:550.
- Seppälä MT, Haltia MJ, Sankila RJ, et al. Long-term outcome after removal of spinal neurofibroma. J Neurosurg 1995; 82:572.
- Thakkar SD, Feigen U, Mautner VF. Spinal tumours in neurofibromatosis type 1: an MRI study of frequency, multiplicity and variety. Neuroradiology 1999; 41:625.
- Patronas NJ, Courcoutsakis N, Bromley CM, et al. Intramedullary and spinal canal tumors in patients with neurofibromatosis 2: MR imaging findings and correlation with genotype. Radiology 2001; 218:434.
- Seppälä MT, Sainio MA, Haltia MJ, et al. Multiple schwannomas: schwannomatosis or neurofibromatosis type 2? J Neurosurg 1998; 89:36.
- Gonzalvo A, Fowler A, Cook RJ, et al. Schwannomatosis, sporadic schwannomatosis, and familial schwannomatosis: a surgical series with long-term follow-up. Clinical article. J Neurosurg 2011; 114:756.
- Pathology and genetics of tumours of the nervous system. In: World Health Organization Classification of Tumours of the Nervous System, Editorial and Consensus Conference Working Group, Louis DN, Ohgaki H, Wiestler OD, Cavenee WK (Eds), IARC Press, Lyon, France 2007.
- Kernohan JW, Sayre GP. Tumors of the Central Nervous System. Fascicle 35, Institute of Pathology; Armed Forces, 1952.
- Seppälä MT, Haltia MJ. Spinal malignant nerve-sheath tumor or cellular schwannoma? A striking difference in prognosis. J Neurosurg 1993; 79:528.
- Conti P, Pansini G, Mouchaty H, et al. Spinal neurinomas: retrospective analysis and long-term outcome of 179 consecutively operated cases and review of the literature. Surg Neurol 2004; 61:34.
- Saiki M, Taguchi T, Kaneko K, et al. Measuring of the compensation of a nerve root in a cervical schwannoma: a case report. J Orthop Sci 2003; 8:714.
- Lohle PN, Wurzer HA, Seelen PJ, et al. Cystic lesions accompanying extra-axial tumours. Neuroradiology 1999; 41:13.
- Krassioukov AV, Sarjeant R, Arkia H, Fehlings MG. Multimodality intraoperative monitoring during complex lumbosacral procedures: indications, techniques, and long-term follow-up review of 61 consecutive cases. J Neurosurg Spine 2004; 1:243.
- Steck JC, Dietze DD, Fessler RG. Posterolateral approach to intradural extramedullary thoracic tumors. J Neurosurg 1994; 81:202.
- O'Toole JE, McCormick PC. Midline ventral intradural schwannoma of the cervical spinal cord resected via anterior corpectomy with reconstruction: technical case report and review of the literature. Neurosurgery 2003; 52:1482.
- Lot G, George B. Cervical neuromas with extradural components: surgical management in a series of 57 patients. Neurosurgery 1997; 41:813.
- McCormick PC. Surgical management of dumbbell and paraspinal tumors of the thoracic and lumbar spine. Neurosurgery 1996; 38:67.
- Seppälä MT, Haltia MJ, Sankila RJ, et al. Long-term outcome after removal of spinal schwannoma: a clinicopathological study of 187 cases. J Neurosurg 1995; 83:621.
- Sohn S, Chung CK, Park SH, et al. The fate of spinal schwannomas following subtotal resection: a retrospective multicenter study by the Korea spinal oncology research group. J Neurooncol 2013; 114:345.