Peripheral nerve sheath tumours
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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:
- Malignant:
Specific diagnoses
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 - diagnostic feature.
- Hyaline thickened blood vessels.
- Thick capsule.
- In the GI tract: classically have a peripheral lymphoid cuff.[2]
- +/-Hemosiderin deposition within tumour.
Notes:
- Tumour does not smear well.[3]
- Antoni A: may look somewhat like scattered matchsticks.
DDx:
- Meningioma.
- Intranodal palisaded myofibroblastoma - if surrounded by a rim of lymphoid tissue, i.e. intranodal.
- Leiomyoma.
Images:
- www:
- WC:
Schwannoma subtypes
There are four:[4]
- Conventional schwannoma.
- Cellular schwannoma.
- Plexiform schwannoma.
- Melanotic schwannoma.
Conventional schwannoma
- Most common.
Cellular schwannoma
- May mimic MPNST.
Images:
Plexiform schwannoma
- May mimic MPNST if cellular - esp. in childhood.
Images:
Melanotic schwannoma
- May be confused with melanoma.
- Psammomatous form (psammomatous melanotic schwannoma) associated with a heritable disorder (Carney complex).
Note:
- Carney complex:[4]
- Cutaneous lentigines.
- Myxomas (skin (subcutaneous), subcutanous, heart).
- Endocrine neoplasms.
Images:
IHC
Features:[5]
- S-100 +ve.
- Glut1 +ve.
- CD34 +ve.
- Cytokeratins ~70% +ve.[citation needed]
- SOX10 +ve.[6]
- -ve in synovial sarcoma, rhabdomyosarcoma, chondrosarcoma.
- EMA -ve. (???)
- Usually +ve (~75% of the time) in meningiomas.[7]
Perineurioma
General
- Benign tumour derived from perineurial cells.
Microscopic
Features:[8]
- Perineural epithelioid cells.
- Abundant pale, fuffy appearing cytoplasm.
Note:
- May be intraneural.[8]
DDx:
- Neuroma.
- Neurofibroma.
- Schwannoma.
- S100 +ve, EMA -ve.[8]
Images:
IHC
- S100 -ve.
- EMA +ve.
- CD34 ~65% +ve.[9]
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.
- +/-Axonal swellings (ovoid pink/purple blobs).
DDx:
- Morton neuroma (foot).
Images:
Palisaded encapsulated neuroma
- Abbreviated PEN.
- AKA palisaded and encapsulated neuroma.
General
- Flesh-colour papule - classically on the face.[11]
- Isolated finding - not associated with a systemic disease or malignancy.[12]
- Superficial skin.[13]
Microscopic
Features:[11]
- Encapsulated dermal spindle cell lesion.
- Fasciular arrangement.
- Neural-type spindle cells:
- Not vacuolated.
- Nuclei have pointy ends.
- Intralesional clefts.
- Useful to differentiate from schwannoma.
DDx:
- Schwannoma:[11]
- No intralesional clefts.
- More variability in the cellularity.
- May be deep.
Other considerations:
- Leiomyoma - cytoplasm not vacuolated, nuclei more elliptical.
Images:
IHC
Features:[12]
- S100 +ve.
- EMA +ve (capsule of lesion).
Neurofibroma
General
- May be a part of neurofibromatosis 1 (NF1).
- A painful skin lesion.
- Composed of Schwann cells, axons, fibrous material.[1]
Classification:[14]
- Localized - sporatic.
- Diffuse - usually poorly defined, young adults and children; sporatic.
- Plexiform - associated with NF1.
Gross/radiologic
Gross features (plexiform NF):[14]
- "Bag of worms" appearance.
Radiologic:[14]
- Fusiform mass.
Microscopic
Features:
- Spindle cells with wavy nuclei without pleomorphism - key feature.
- Often described as "shredded carrots".
- May be arranged in fascicles and intermixed with collagen.
- Often no pattern is apparent.
- Moderate increase of cellularity vis-a-vis normal dermis.
- May be poorly or well-circumscribed.
- +/-Plexiform growth pattern - "bag of worms".[1]
- Multiple well-circumscribed nests.
- Mast cells[15] - one has to look for them at high power.
- Very useful for confirming the low power suspicion.
DDx:
- Schwannoma.
- Dermatofibrosarcoma protuberans (DFSP) - S-100 -ve, CD34 +ve.
- Ganglioneuroma.
Images:
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IHC
Features:[5]
- S100 +ve.
- CD34 +ve.
- Glut1 +ve.
- EMA +ve/-ve.
Neurothekeoma
General
- Rare.
- Female > male.
Microscopic
Features:[16]
- Superficial dermal lesion:
- Usu. lobulated or micronodular architecture - key feature.
- +/-Focal sheeting.
- Spindle/epithelioid morphology with pale eosinophilic cytoplasm - key feature.
- +/-Inflammation around lesion.
- +/-Surrounded by collagen.
- Usu. lobulated or micronodular architecture - key feature.
Notes:
- No atypia.
- Mitoses rare/none.
- Often poorly circumscribed.
Subtypes:[17]
- Cellular.
- Myxoid.
- Intermediate.
DDx:
- Dermatofibroma.
- Angiomatoid fibrous histiocytoma -- have cystic blood filled spaces, inflammation.[18]
Images:
IHC
Features:[16]
- NKI/C3 (AKA NKI-C3) +ve.
- NSE +/-ve.
Others:[19]
- Vimentin +ve.
- CD10 +ve.
- Microphthalmia transcription factor +ve.
- PGP9.5 +ve.
Exclusionary:
- S100 -ve.
- Exclude other peripheral nerve sheath tumours. (???)
Malignant peripheral nerve sheath tumour
General
- Malignant - as the name implies.
- Usu. assoc. with a peripheral nerve.[citation needed]
- May be seen in the context of neurofibromatosis type 1.
Microscopic
Features:
- Cellular.
- Nuclear atypia.
- Mitoses.
- +/-Herring bone pattern.
Notes:
- May be diagnosed in a poorly diff. tumour if patient has NF1.
DDx:
- Cellular schwannoma.
- Plexiform schwannoma.
- Malignant triton tumour.
DDx of herring bone:
- MPNST.
- Synovial sarcoma.
- Fibrosarcoma.
Images:
- MPNST - intermed. mag. (WC).
- MPNST - high mag. (WC).
- MPNST - several images (upmc.edu).
- MPNST - case 2 - several images (upmc.edu).
Grading
Sarcoma grading system[23] - based on:
- Tumour differentiation.
- Mitotic rate.
- Necrosis.
IHC
Features:[6]
- S-100 +ve ~ 30% of tumours.
- SOX10 +ve ~ 50% of tumours.
Others:[21]
- p53.
- p16.
- p27.
- MIB1.
Malignant triton tumour
- Abbreviated MTT.
- AKA malignant peripheral nerve sheath tumor with rhabdomyosarcomatous differentiation.[24]
General
- Rare.
- Considered to be a variant of MPNST.
- Prognosis worse that conventional MPNST.[24]
- Five year survival ~14%.[25]
- Diagnosis may require clinical information, i.e. individual has a history of neurofibromatosis type 1 (NF1).
Note:
- A handful of benign triton tumours are reported; these are considered neuromuscular hamartomas.[26]
Microscopic
Features - Woodruff criteria - all three required:[24]
- (a) Tumour arise from a peripheral nerve or (b) individual has NF1 or (c) lesion a metastasis arising in the context of (a) or (b).
- Schwann cell tumour characteristics.
- Rhabdomyoblasts.
- Eccentric nucleus.
- Moderate amount of eosinophilic cytoplasm.
- +/-Cross-striations.
DDx:
- Malignant peripheral nerve sheath tumour.
- Adult fibrosarcoma.
- Synovial sarcoma.
- Rhabdomyosarcoma.
- Carcinosarcoma.
IHC
Features:
- S100 +ve/-ve -- usu. focal if positive.[24]
- Leu-7 +ve/-ve.
- Myelin basic protein +ve/-ve.
Rhabdomyoblastic differentiation:[24]
- Desmin.
- Actin.
- Myogenin.
EM
- +/-Sarcomeres.[24]
Morton neuroma
General
- Benign foot condition.
- Uncommon.
- Usu. interdigital nerves.
Etiology:
- Indirect nerve trauma.
Clinical:[27]
- Foot pain.
Microscopic
Features:[27]
- Extensive fibrosis around and within the nerve.
- Digital artery:
- +/-Thrombosis.
- +/-Arterial thickening.
DDx:
Image:
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.
- ↑ 5.0 5.1 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.
- ↑ 6.0 6.1 Nonaka D, Chiriboga L, Rubin BP (September 2008). "Sox10: a pan-schwannian and melanocytic marker". Am. J. Surg. Pathol. 32 (9): 1291–8. doi:10.1097/PAS.0b013e3181658c14. PMID 18636017.
- ↑ Rushing, EJ.; Bouffard, JP.; McCall, S.; Olsen, C.; Mena, H.; Sandberg, GD.; Thompson, LD. (Jun 2009). "Primary extracranial meningiomas: an analysis of 146 cases.". Head Neck Pathol 3 (2): 116-30. doi:10.1007/s12105-009-0118-1. PMID 19644540.
- ↑ 8.0 8.1 8.2 Mills, Stacey E; Carter, Darryl; Greenson, Joel K; Reuter, Victor E; Stoler, Mark H (2009). Sternberg's Diagnostic Surgical Pathology (5th ed.). Lippincott Williams & Wilkins. pp. 424. ISBN 978-0781779425.
- ↑ 9.0 9.1 Hornick, JL.; Fletcher, CD. (Jul 2005). "Soft tissue perineurioma: clinicopathologic analysis of 81 cases including those with atypical histologic features.". Am J Surg Pathol 29 (7): 845-58. PMID 15958848.
- ↑ Tsang, WY.; Chan, JK.; Chow, LT.; Tse, CC. (Aug 1992). "Perineurioma: an uncommon soft tissue neoplasm distinct from localized hypertrophic neuropathy and neurofibroma.". Am J Surg Pathol 16 (8): 756-63. PMID 1497116.
- ↑ 11.0 11.1 11.2 Busam, Klaus J. (2009). Dermatopathology: A Volume in the Foundations in Diagnostic Pathology Series (1st ed.). Saunders. pp. 536. ISBN 978-0443066542.
- ↑ 12.0 12.1 12.2 Newman, MD.; Milgraum, S. (2008). "Palisaded encapsulated neuroma (PEN): an often misdiagnosed neural tumor.". Dermatol Online J 14 (7): 12. PMID 18718196.
- ↑ S. Sade. 8 September 2011.
- ↑ 14.0 14.1 14.2 Wilkinson, LM.; Manson, D.; Smith, CR. (Oct 2004). "Best cases from the AFIP: plexiform neurofibroma of the bladder.". Radiographics 24 Suppl 1: S237-42. doi:10.1148/rg.24si035170. PMID 15486243.
- ↑ Staser, K.; Yang, FC.; Clapp, DW. (Jul 2010). "Mast cells and the neurofibroma microenvironment.". Blood 116 (2): 157-64. doi:10.1182/blood-2009-09-242875. PMID 20233971.
- ↑ 16.0 16.1 Hornick JL, Fletcher CD (March 2007). "Cellular neurothekeoma: detailed characterization in a series of 133 cases". Am. J. Surg. Pathol. 31 (3): 329–40. doi:10.1097/01.pas.0000213360.03133.89. PMID 17325474.
- ↑ Wang AR, May D, Bourne P, Scott G (November 1999). "PGP9.5: a marker for cellular neurothekeoma". Am. J. Surg. Pathol. 23 (11): 1401–7. PMID 10555009.
- ↑ URL: http://surgpathcriteria.stanford.edu/softfib/angiomatoid_fibrous_histiocytoma/. Accessed on: 11 May 2011.
- ↑ Fetsch JF, Laskin WB, Hallman JR, Lupton GP, Miettinen M (July 2007). "Neurothekeoma: an analysis of 178 tumors with detailed immunohistochemical data and long-term patient follow-up information". Am. J. Surg. Pathol. 31 (7): 1103–14. doi:10.1097/PAS.0b013e31802d96af. PMID 17592278.
- ↑ Mills, AM.; Karamchandani, JR.; Vogel, H.; Longacre, TA. (Mar 2011). "Endocervical fibroblastic malignant peripheral nerve sheath tumor (neurofibrosarcoma): report of a novel entity possibly related to endocervical CD34 fibrocytes.". Am J Surg Pathol 35 (3): 404-12. doi:10.1097/PAS.0b013e318208f72e. PMID 21317712.
- ↑ 21.0 21.1 Zhou H, Coffin CM, Perkins SL, Tripp SR, Liew M, Viskochil DH (October 2003). "Malignant peripheral nerve sheath tumor: a comparison of grade, immunophenotype, and cell cycle/growth activation marker expression in sporadic and neurofibromatosis 1-related lesions". Am. J. Surg. Pathol. 27 (10): 1337–45. PMID 14508395.
- ↑ Kar M, Deo SV, Shukla NK, et al. (2006). "Malignant peripheral nerve sheath tumors (MPNST)--clinicopathological study and treatment outcome of twenty-four cases". World J Surg Oncol 4: 55. doi:10.1186/1477-7819-4-55. PMC 1560134. PMID 16923196. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1560134/.
- ↑ Trojani M, Contesso G, Coindre JM, et al. (January 1984). "Soft-tissue sarcomas of adults; study of pathological prognostic variables and definition of a histopathological grading system". Int. J. Cancer 33 (1): 37–42. PMID 6693192.
- ↑ 24.0 24.1 24.2 24.3 24.4 24.5 Stasik, CJ.; Tawfik, O. (Dec 2006). "Malignant peripheral nerve sheath tumor with rhabdomyosarcomatous differentiation (malignant triton tumor).". Arch Pathol Lab Med 130 (12): 1878-81. doi:10.1043/1543-2165(2006)130[1878:MPNSTW]2.0.CO;2. PMID 17149968.
- ↑ McConnell, YJ.; Giacomantonio, CA. (Jan 2012). "Malignant triton tumors-complete surgical resection and adjuvant radiotherapy associated with improved survival.". J Surg Oncol. doi:10.1002/jso.23042. PMID 22253011.
- ↑ Castro, DE.; Raghuram, K.; Phillips, CD. (Apr 2005). "Benign triton tumor of the trigeminal nerve.". AJNR Am J Neuroradiol 26 (4): 967-9. PMID 15814954.
- ↑ 27.0 27.1 Mills, Stacey E; Carter, Darryl; Greenson, Joel K; Oberman, Harold A; Reuter, Victor E (2004). Sternberg's Diagnostic Surgical Pathology (4th ed.). Lippincott Williams & Wilkins. pp. 243. ISBN 978-0781740517.