====== Spinal schwannoma epidemiology ======

{{rss>https://pubmed.ncbi.nlm.nih.gov/rss/search/18SX-0JF_oBtJkBGdpRDhqxuwE-s9oKcyQJ34JLTQMAwhZOcfT/?limit=15&utm_campaign=pubmed-2&fc=20240320194528}}

Most intradural tumors are located within the intradural extramedullary compartment, and the most common tumors are spinal schwannomas and meningiomas. Other less common neoplasms include [[neurofibroma]], [[solitary fibrous tumor]],[[myxopapillary ependymoma]], lymphoma, metastatic leptomeningeal disease, malignant peripheral nerve sheath tumor, and [[paraganglioma]]. 
((Puac-Polanco P, Guarnizo A, Cruz JP, Rodriguez FR, Torres CH. Intradural Extramedullary Tumors and Associated Syndromes. Neuroimaging Clin N Am. 2023 Aug;33(3):407-422. doi: 10.1016/j.nic.2023.03.002. Epub 2023 Apr 25. PMID: 37356859.)).

----

[[Spinal schwannoma]] is most frequently seen in the cervical and lumbar regions, far more frequently than in the [[thoracic]] spine.

The [[incidence]] of [[spinal schwannoma]] is 0.3–0.5/100,000 individuals annually 
((Seppala MT, Haltia MJ, Sankila RJ, Jaaskelainen JE, Heiskanen O. Long-term outcome after removal of spinal schwannoma: a clinicopathologi- cal study of 187 cases. J Neurosurg (1995) 83:621–6. doi:10.3171/jns.1995. 83.4.0621)).

Its [[prevalence]] is similar in [[male]]s and [[female]]s, and it is usually diagnosed during the fourth and fifth decades of life
((Jinnai T, Koyama T. Clinical characteristics of spinal nerve sheath tumors: analysis of 149 cases. Neurosurgery (2005) 56:510–5. doi:10.1227/01. NEU.0000153752.59565.BB)).

Schwannomas have an incidence of 3% of all [[spinal tumor]]s.

Most occur sporadically and are solitary, but they may also be associated with [[Neurofibromatosis type 2]], but can occur with [[Neurofibromatosis type 1]].

Spinal schwannoma constitutes approximately 25% of the [[intradural spinal tumor]]s
((Engelhard HH, Villano JL, Porter KR, et al. Clinical presentation, histology, and treatment in 430 patients with primary tumors of the spinal cord, spinal meninges, or cauda equina. J Neurosurg Spine. 2010;13:67–77.))
((Safavi-Abbasi S, Senoglu M, Theodore N, et al. Microsurgical management of spinal schwannomas: evaluation of 128 cases. J Neurosurg Spine. 2008;9:40–47.))
((Holland K, Kaye AH. Spinal tumors in neurofibromatosis-2: management considerations - a review. J Clin Neurosci. 2009;16:169–177.))
((Klekamp J, Samii M. Surgery of spinal nerve sheath tumors with special reference to neurofibromatosis. Neurosurgery. 1998;42:279–289.))
((Celli P, Trillò G, Ferrante L. Spinal extradural schwannoma. J Neurosurg Spine. 2005;2:447–456.))
((Jankowski R, Szmeja J, Nowak S, Sokół B, Blok T. Giant schwannoma of the lumbar spine: a case report. Neurol Neurochir Pol. 2010;44:91–95.))
((Conti P, Pansini G, Mouchaty H, Capuano C, Conti R. Spinal
neurinomas: retrospective analysis and long-term outcome of
179 consecutively operated cases and review of the literature.
Surg Neurol 2004; 61: 34-43.)).
((Seppälä MT, Haltia MJ, Sankila RJ, Jääskeläinen JE, Heiskanen O. Long-term
outcome after removal of spinal schwannoma: a clinicopathological study of 187
cases. J Neurosurg. 1995 Oct;83(4):621-6. PubMed PMID: 7674010.
))
((De Verdelhan O, Haegelen C, Carsin-Nicol B, et al. MR imaging features of spinal schwannomas and meningiomas. J Neuroradiol. 2005;32:42–49.))
((Ahn DK, Park HS, Choi DJ, Kim KS, Kim TW, Park SY. The surgical treatment for spinal intradural extramedullary tumors. Clin Orthop Surg. 2009;1:165–172.))
((Sim JE, Noh SJ, Song YJ, Kim HD. Removal of intradural-extramedullary spinal cord tumors with unilateral limited laminectomy. J Korean Neurosurg Soc. 2008;43:232–236.))
((McCormick PC, Post KD, Stein BM. Intradural extramedullary tumors in adults. Neurosurg Clin N Am. 1990;1:591–608.)).

Except in cases of [[neurofibromatosis]], it is very rare for [[tumor]]s of different pathological types to exist concurrently at the same spinal level, with only 9 cases reported to date, in which [[spinal meningioma]] was found with [[spinal schwannoma]] in 7 cases and with [[spinal neurofibroma]] in 2 cases
((Zhan Z, Yan X, Nie W, Ding Y, Xu W, Huang H. Neurofibroma and Meningioma
within a Single Dumbbell-Shaped Tumor at the Same Cervical Level without
Neurofibromatosis: a Case Report and Literature Review. World Neurosurg. 2019 Jun
26. pii: S1878-8750(19)31788-7. doi: 10.1016/j.wneu.2019.06.142. [Epub ahead of
print] PubMed PMID: 31254713.
)).

====Configuration====
In a paraspinal location, they are the commonest cause of intradural extramedullary tumors but may also be extradural or extramedullary 
((Wein S, Gaillard F. Intradural spinal tumours and their mimics: A review of radiographic features. Postgrad Med J. 2013;89(1054):457–69.)).

Most are entirely intradural, but 8-32 % may be completely extradural
((Seppälä MT, Haltia MJ, Sankila RJ, Jääskeläinen JE, Heiskanen O. Long-term
outcome after removal of spinal schwannoma: a clinicopathological study of 187
cases. J Neurosurg. 1995 Oct;83(4):621-6. PubMed PMID: 7674010.
))
((Conti P, Pansini G, Mouchaty H, Capuano C, Conti R. Spinal
neurinomas: retrospective analysis and long-term outcome of
179 consecutively operated cases and review of the literature.
Surg Neurol 2004; 61: 34-43.)).
1-19 % are a combination, 6-23 % are [[dumbbell spinal schwannoma]]s, and 1 % are [[intramedullary schwannoma]]s.

The most common location of spinal schwannomas are the [[lumbar spine]] (48%)
((Conti P, Pansini G, Mouchaty H, Capuano C, Conti R. Spinal
neurinomas: retrospective analysis and long-term outcome of
179 consecutively operated cases and review of the literature.
Surg Neurol 2004; 61: 34-43.)).

Schwannomas are frequently located in the extramedullary region, and may present as dumbbell shaped in 10-15% of cases. They may also be located at the intramedullary region. Ten percent of the tumors were in the extradural location, and 1% in the intradural intramedullary regional location.

Up to 2.7% of schwannomas are located in the retroperitoneal region
((Cury J, Coelho RF, Srougi M. Retroperitoneal schwannoma: Case series and literature review. Clin São Paulo Braz. 2007;62(3):359–62.)). 

Most arise from the [[dorsal root of spinal nerve]] (sensory) rootlets (75%).
Paraspinal schwannomas involve the dorsal nerve roots, affecting people in the fourth and fifth decades of life 
((Chamberlain MC, Tredway TL. Adult primary intradural spinal cord tumors: A review. Curr Neurol Neurosci Rep. 2011;11(3):320–8.)).


===== References =====