Schwannoma pathophysiology: Difference between revisions
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===Spontaneous=== | ===Spontaneous=== | ||
Familial tumor syndromes | |||
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==Genetics== | ==Genetics== | ||
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*Antoni type B pattern cells are less compact and are prone to cystic degeneration. | *Antoni type B pattern cells are less compact and are prone to cystic degeneration. | ||
[[File:Rcse9407-e10-03.jpg|300px|thumb|none|Microscopic images of the ancient schwannoma: spindle cells arranged in short fascicles with focal vague Verocay bodies (haematoxylin and eosin [H&E] stain, 100x magnification) (top left), schwannoma with focal collection of haemosiderin laden macrophages (H&E stain, 100x magnification) (top right), cholesterol clefts in ancient schwannoma (H&E stain, 100x magnification) (bottom left) and spindle cells immunoreactive for S100 protein (nuclear positivity) (indirect immunoperoxidase staining, 100x magnification) (bottom right),Sayed SI, Rane P, Deshmukh A, et al. Ancient schwannoma of the parapharynx causing dysphagia: a rare entity. Ann R Coll Surg Engl. 2012;94(7):e217–e220. doi:10.1308/003588412X13373405385737,https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3954264/]] | |||
===== Variants ===== | ===== Variants ===== | ||
Schwannoma variants include 6,8: | Schwannoma variants include 6,8: | ||
Revision as of 23:32, 27 October 2019
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: ; Maneesha Nandimandalam, M.B.B.S.[2]
Overview
Pathophysiology
Spontaneous
Familial tumor syndromes
Genetics
- Loss of function of a tumor suppressor gene called merlin gene, either by:
- Direct genetic change involving the NF2 gene on chromosome 22
- Secondarily to merlin inactivation
Associated Conditions
- Neurofibromatosis type 2 (NF2)[1]
- Schwannomatosis
- Carney's complex
Gross and Microscopic Pathology
Microscopic appearance
- Conventional schwannomas are composed of spindle cells which demonstrate two growth patterns: Antoni type A and Antoni type B 7,8.[2][3][4]
- Antoni type A pattern: elongated cells are densely packed and arranged in fascicles. Palisades are sometimes seen; when prominent these form Verocay bodies.
- Antoni type B pattern cells are less compact and are prone to cystic degeneration.
Variants
Schwannoma variants include 6,8:
- ancient schwannoma
- cellular schwannoma
- predominantly composed of Antoni A tissue
- no Verocay bodies
- most commonly found in a paravertebral location, or trigeminal nerves (CN V)
- melanotic schwannoma: dense melanin pigment
- plexiform schwannoma[5]
- usually arise from skin or subcutaneous tissues
- usually diagnosed at birth or childhood
- usually sporadic, but rarely associated with NF2
- should not be confused with plexiform neurofibromas
- associated with NF1
- may undergo malignant change
Immunohistochemistry
References
- ↑ Hilton DA, Hanemann CO (April 2014). "Schwannomas and their pathogenesis". Brain Pathol. 24 (3): 205–20. doi:10.1111/bpa.12125. PMID 24450866.
- ↑ Doddrell RD, Dun XP, Shivane A, Feltri ML, Wrabetz L, Wegner M; et al. (2013). "Loss of SOX10 function contributes to the phenotype of human Merlin-null schwannoma cells". Brain. 136 (Pt 2): 549–63. doi:10.1093/brain/aws353. PMC 3572932. PMID 23413263.
- ↑ Sayed SI, Rane P, Deshmukh A, Chaukar D, Menon S, Arya S; et al. (2012). "Ancient schwannoma of the parapharynx causing dysphagia: a rare entity". Ann R Coll Surg Engl. 94 (7): e217–20. doi:10.1308/003588412X13373405385737. PMC 3954264. PMID 23031754.
- ↑ Giovannini M, Bonne NX, Vitte J, Chareyre F, Tanaka K, Adams R; et al. (2014). "mTORC1 inhibition delays growth of neurofibromatosis type 2 schwannoma". Neuro Oncol. 16 (4): 493–504. doi:10.1093/neuonc/not242. PMC 3956353. PMID 24414536.
- ↑ Tchernev G, Chokoeva AA, Patterson JW, Bakardzhiev I, Wollina U, Tana C (February 2016). "Plexiform Neurofibroma: A Case Report". Medicine (Baltimore). 95 (6): e2663. doi:10.1097/MD.0000000000002663. PMC 4753888. PMID 26871793.