====== Schwannoma ======

{{rss>https://pubmed.ncbi.nlm.nih.gov/rss/search/1DeUIcPgNLDJQT1TOHN6OSdQmAXRuwMpRYWeNzx_2q3BrhlQzl/?limit=15&utm_campaign=pubmed-2&fc=20240320194217}}

Schwannomas are [[benign tumor]]s that are typically round, well-demarcated, and encapsulated, composed of [[Schwann cell]]s; the [[tumor]]s can grow anywhere throughout the nervous system that contains [[Schwann cell]]s.

The absence of the [[protein]] [[NF2]]/[[Merlin]] causes an uninterrupted [[cell proliferation]] cascade originating from an abnormal interaction between an extracellular [[mucopolysaccharide]], hyaluronan (HA), and [[schwann cell]] surface [[CD44]] receptor, which has been identified as one of the central causative factors for schwannoma
((Ariyannur PS, Vikkath N, Pillai AB. Cerebrospinal Fluid Hyaluronan and
Neurofibromatosis Type 2. Cancer Microenviron. 2018 Aug 25. doi:
10.1007/s12307-018-0216-2. [Epub ahead of print] PubMed PMID: 30145722.
)).

It has been described that a schwannoma may display variable degenerative changes such as fibrosis, cytological atypia, calcification, hemorrhage, or cystic formations 
((Borges G, Bonilha L, Proa M Jr, Fernandes YB, Ramina R, Zanardi V, et al. Imaging features and treatment of an intradural lumbar cystic schwannoma. Arq Neuropsiquiatr 2005; 63: 681-684.)).

Cystic degenerations occurring in schwannomas are found in schwannomas of the orbital region, olfactory groove, tentorial hiatus, posterior cavernous sinus, presacral region, maxillary sinus, intramedullary spinal region, or intraventicular region
((Borges G, Bonilha L, Proa M Jr, Fernandes YB, Ramina R, Zanardi V, et al. Imaging features and treatment of an intradural lumbar cystic schwannoma. Arq Neuropsiquiatr 2005; 63: 681-684.)).

===== Classification =====
[[Schwannoma Classification]].

===== Epidemiology =====
Schwannomas, also known as the [[nerve sheath tumor]]s, [[neurinoma]]s or [[neurilemmoma]]s, are the most common type of [[intraspinal tumor]]s, which are frequently observed in the cervical and lumbar regions 

===== Diagnosis =====
[[Schwannoma Diagnosis]]

===== Differential Diagnosis =====

Schwannoma vs. neurofibroma. While similar in many ways, these tumors differ histologically. Schwannomas (née: neurilemmomas) arise from Schwann cells, which produce myelin. Neurofibromas consist of neurites (axons or dendrites of immature or developing neurons), Schwann’s cells, and fibroblasts within a collagenous or myxoid matrix. In contrast to schwannomas which displace axons