Difference between revisions of "Peripheral nerve sheath tumours"

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(→‎Traumatic neuroma: +palisaded and encapsulated neuroma)
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Features:
Features:
*Nerve with adjacent small organized micro-fascicles in collagen - as seen in regeneration.
*Nerve with adjacent small organized micro-fascicles in collagen - as seen in regeneration.
==Palisaded encapsulated neuroma==
*Abbreviated ''PEN''.
*[[AKA]] ''palisaded and encapsulated neuroma''.
===General===
*Flesh-colour papule - classically on the face.<ref name=Ref_Derm536>{{Ref Derm|536}}</ref>
*Isolated finding - not associated with a systemic disease or malignancy.<ref name=pmid18718196>{{Cite journal  | last1 = Newman | first1 = MD. | last2 = Milgraum | first2 = S. | title = Palisaded encapsulated neuroma (PEN): an often misdiagnosed neural tumor. | journal = Dermatol Online J | volume = 14 | issue = 7 | pages = 12 | month =  | year = 2008 | doi =  | PMID = 18718196 }}</ref>
===Microscopic===
Features:<ref name=Ref_Derm536>{{Ref Derm|536}}</ref>
*Encapsulated dermal spindle cell lesion.
**Fasciular arrangement.
DDx:
*[[Schwannoma]].
Other considerations:
*[[Leiomyoma]] - cytoplasm not vacuolated, nuclei more elliptical.
Images:
*[http://dermatology.cdlib.org/147/case_presentation/pen/2.jpg PEN (cdlib.org)].<ref name=pmid18718196>{{Cite journal  | last1 = Newman | first1 = MD. | last2 = Milgraum | first2 = S. | title = Palisaded encapsulated neuroma (PEN): an often misdiagnosed neural tumor. | journal = Dermatol Online J | volume = 14 | issue = 7 | pages = 12 | month =  | year = 2008 | doi =  | PMID = 18718196 }}</ref>
===IHC===
Features:<ref name=pmid18718196/>
*S100 +ve.
*EMA +ve (capsule of lesion).


==Neurofibroma==
==Neurofibroma==

Revision as of 16:33, 2 September 2011

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

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]

  1. Conventional.
    • Most common.
  2. Cellular.
  3. Plexiform.
    • May mimic MPNST if cellular - esp. in childhood.
  4. Melanotic.
    • May be confused with melanoma.
    • Psammomatous form (psammomatous melanotic schwannoma) associated with a heritable disorder (Carney complex).

Notes:

  • Carney complex:[4]
    • Cutaneous lentigines.
    • Myxomas (skin (subcutaneous), subcutanous, heart).
    • Endocrine neoplasms.

IHC

Features:[5]

Perineurioma

General

  • Benign tumour derived from perineurial cells.

Microscopic

Features:[7]

  • Long slender spindle cells with:
    • Small spindle-shaped nuclei.

DDx:

  • Neuroma.
  • Neurofibroma.
  • Schwannoma.

Image:

IHC

Features:[7]

  • S100 -ve.
  • EMA +ve.

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.

Palisaded encapsulated neuroma

  • Abbreviated PEN.
  • AKA palisaded and encapsulated neuroma.

General

  • Flesh-colour papule - classically on the face.[8]
  • Isolated finding - not associated with a systemic disease or malignancy.[9]

Microscopic

Features:[8]

  • Encapsulated dermal spindle cell lesion.
    • Fasciular arrangement.

DDx:

Other considerations:

  • Leiomyoma - cytoplasm not vacuolated, nuclei more elliptical.

Images:

IHC

Features:[9]

  • S100 +ve.
  • EMA +ve (capsule of lesion).

Neurofibroma

General

Classification:[10]

  1. Localized - sporatic.
  2. Diffuse - usu. poorly defined, young adults and children; sporatic.
  3. Plexiform - assoc. with NF1.

Gross/radiologic

Gross features (plexiform NF):[10]

  • "Bag of worms" appearance.

Radiologic:[10]

  • Fusiform mass.

Microscopic

Features:

  • Spindle cells with wavy nuclei without pleomorphism - key feature.
  • May be arranged in fascicles intermixed and 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]

DDx:

Image:

www:

IHC

Features:[5]

  • S100 +ve.
  • CD34 +ve.
  • Glut1 +ve.
  • EMA +ve/-ve.

Neurothekeoma

General

  • Rare.
  • Female > male.

Microscopic

Features:[11]

  • Dermal spindle cell lesion.
  • +/-Inflammation around lesion.

Notes:

  • No atypia.
  • Mitoses rare/none.

Subtypes:[12]

  • Cellular.
  • Myxoid.
  • Intermediate.

DDx:

  • Dermatofibroma.
  • Angiomatoid fibrous histiocytoma -- have cystic blood filled spaces, inflammation.[13]

Image(s):

IHC

Features:[11]

  • NKI/C3 (AKA NKI-C3) +ve.
  • NSE +/-ve.

Others:[14]

  • Vimentin +ve.
  • CD10 +ve.
  • Microphthalmia transcription factor +ve.
  • PGP9.5 +ve.

Exclusionary:

  • S100 -ve.
    • Exclude other peripheral nerve sheath tumours. (???)

Malignant peripheral nerve sheath tumours

General

  • Malignant - as the name implies.
  • Usu. assoc. with a peripheral nerve.[citation needed]

Microscopic

Features:

  • Cellular.
  • Nuclear atypia.
  • Mitoses.

DDx:

  • Cellular schwannoma.
  • Plexiform schwannoma.

Image(s):

Notes:

  • May be diagnosed in a poorly diff. tumour if patient has NF1.

Grading

  • Can be graded histologically,[15] and this is prognostic.[16]

Sarcoma grading system[17] - based on:

  • Tumour differentiation.
  • Mitotic rate.
  • Necrosis.

IHC

Features:[6]

  • S-100 +ve ~ 30% of tumours.
  • SOX10 +ve ~ 50% of tumours.

Others:[15]

  • p53.
  • p16.
  • p27.
  • MIB-1.

See also

References

  1. 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.
  2. 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.
  3. MUN. 24 November 2010.
  4. 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. 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. 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.
  7. 7.0 7.1 URL: http://www.pathconsultddx.com/pathCon/diagnosis?pii=S1559-8675%2806%2970452-1. Accessed on: 13 May 2011.
  8. 8.0 8.1 Busam, Klaus J. (2009). Dermatopathology: A Volume in the Foundations in Diagnostic Pathology Series (1st ed.). Saunders. pp. 536. ISBN 978-0443066542.
  9. 9.0 9.1 9.2 Newman, MD.; Milgraum, S. (2008). "Palisaded encapsulated neuroma (PEN): an often misdiagnosed neural tumor.". Dermatol Online J 14 (7): 12. PMID 18718196.
  10. 10.0 10.1 10.2 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.
  11. 11.0 11.1 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.
  12. 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.
  13. URL: http://surgpathcriteria.stanford.edu/softfib/angiomatoid_fibrous_histiocytoma/. Accessed on: 11 May 2011.
  14. 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.
  15. 15.0 15.1 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.
  16. 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/.
  17. 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.