Peripheral nerve sheath tumours
Peripheral nerve sheath tumours, abbreviated PNSTs, are common in neuropathology and occasionally show-up elsewhere. A very common PNST is the schwannoma.
Classification
A classification:[1]
- Benign:
- Schwannoma.
- Neurofibroma.
- Perineurioma.
- Traumatic neuroma.
- Malignant:
- Malignant peripheral nerve sheath tumour (MPNST).
Schwannoma
General
- A common neuropathology tumour that occasionally shows-up elsewhere.
- Tumour of tissue surrounding a nerve.
- Axons adjacent to the tumour are normal... but may be compressed.
- May be a part of neurofibromatosis type 2.
Microscopic
Features:[1]
- Antoni A:
- Cellular.
- 'Fibrillary, polar, elongated'.
- Antoni B:
- Pauci-cellular.
- Loose microcystic tissue.
- Verocay bodies - paucinuclear area surrounded by nuclei.
- In the GI tract: classically have a peripheral lymphoid cuff.[2]
Notes:
- Tumour does not smear well.[3]
- Antoni A: may look somewhat like scattered matchsticks.
Micrographs:
Subtypes
There are four:[4]
- Conventional.
- Most common.
- Cellular.
- May mimic MPNST.
- Plexiform.
- May mimic MPNST if cellular - esp. in childhood.
- Melanotic.
- May be confused with melanoma.
- Psammomatous form associated with a heritable disorder (Carney complex).
Notes:
Traumatic neuroma
General
- Consequence of trauma -- diagnosis requires history of trauma.
Microscopic
Features:
- Nerve with adjacent small organized micro-fascicles in collagen - as seen in regeneration.
Neurofibroma
General
- May be a part of neurofibromatosis 1.
- Composed of Schwann cells, axons, fibrous material.[1]
Microscopic
Features:[1]
- Plexiform growth pattern - "bag of worms".
DDx:
- Schwannoma.
- Dermatofibrosarcoma protuberans (DFSP) - S-100 -ve, CD34 +ve.
- Ganglioneuroma.
Image:
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IHC
Features:[5]
- S100 +ve.
- CD34 +ve.
- Glut1 +ve.
- EMA +ve/-ve.
Malignant peripheral nerve sheath tumours
General
- Malignant - as the name implies.
Microscopic
Features:
- Cellular.
- Mitoses.
DDx:
- Cellular schwannoma.
- Plexiform schwannoma.
Image(s):
See also
References
- ↑ 1.0 1.1 1.2 1.3 Wippold FJ, Lubner M, Perrin RJ, Lämmle M, Perry A (October 2007). "Neuropathology for the neuroradiologist: Antoni A and Antoni B tissue patterns". AJNR Am J Neuroradiol 28 (9): 1633–8. doi:10.3174/ajnr.A0682. PMID 17893219. http://www.ajnr.org/cgi/reprint/28/9/1633.
- ↑ Levy AD, Quiles AM, Miettinen M, Sobin LH (March 2005). "Gastrointestinal schwannomas: CT features with clinicopathologic correlation". AJR Am J Roentgenol 184 (3): 797–802. PMID 15728600. http://www.ajronline.org/cgi/content/full/184/3/797.
- ↑ MUN. 24 November 2010.
- ↑ 4.0 4.1 Kurtkaya-Yapicier O, Scheithauer B, Woodruff JM (July 2003). "The pathobiologic spectrum of Schwannomas". Histol. Histopathol. 18 (3): 925–34. PMID 12792904.
- ↑ Hirose T, Tani T, Shimada T, Ishizawa K, Shimada S, Sano T (April 2003). "Immunohistochemical demonstration of EMA/Glut1-positive perineurial cells and CD34-positive fibroblastic cells in peripheral nerve sheath tumors". Mod. Pathol. 16 (4): 293–8. doi:10.1097/01.MP.0000062654.83617.B7. PMID 12692193. http://www.nature.com/modpathol/journal/v16/n4/full/3880761a.html.
- ↑ URL: http://www.sarctrials.org/SARC006MPNST. Accessed on: 5 December 2010.