Difference between revisions of "Peripheral nerve sheath tumours"

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(→‎Neurothekeoma: split out)
 
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==Perineurioma==
==Perineurioma==
===General===
{{Main|Perineurioma}}
*Benign tumour derived from perineurial cells (intraneural or soft tissue).
**ICD-O 9571/0
** WHO grade I
*Rarely malignant soft tissue perineurioma.
 
Variant:
*Reticular perineurioma.<ref name=pmid11257623>{{Cite journal  | last1 = Graadt van Roggen | first1 = JF. | last2 = McMenamin | first2 = ME. | last3 = Belchis | first3 = DA. | last4 = Nielsen | first4 = GP. | last5 = Rosenberg | first5 = AE. | last6 = Fletcher | first6 = CD. | title = Reticular perineurioma: a distinctive variant of soft tissue perineurioma. | journal = Am J Surg Pathol | volume = 25 | issue = 4 | pages = 485-93 | month = Apr | year = 2001 | doi =  | PMID = 11257623 }}</ref>
 
===Macroscopy===
*Intraneural perineurioma: segmental tubular enlargement of the nerve.
*Soft tissue perineurioma: Well circumscribed, but not encapsulated.
 
===Microscopic===
Features:<ref name=Ref_Sternberg5_424>{{Ref Sternberg5|424}}</ref>
*Perineural epithelioid cells.
**Abundant pale, fluffy appearing cytoplasm.
 
Note:
*May be intraneural.<ref name=Ref_Sternberg5_424>{{Ref Sternberg5|424}}</ref>
**Typical pseudo-onion bulbs.
**Long considered hypertrophic neuropathy.
**Rare (less than 1% of all nerve sheath tumours).
 
DDx:
*[[Neuroma]].
*[[Neurofibroma]].
*[[Schwannoma]].
**S100 +ve, EMA -ve.<ref name=Ref_Sternberg5_424>{{Ref Sternberg5|424}}</ref>
*[[Liposarcoma]] - reticular perineurioma.
 
Images:
*[http://www.conganat.org/seap/reuniones/almagro2000/scruz/tnerviog5.htm Perineurioma (conganat.org)].
 
<gallery>
File:Perineurioma,_HE_stain.jpg | Pseudo-onion bulbs in a intraneural perioneurioma (WC/jensflorian)
</gallery>
 
===IHC===
Features:<ref name=pmid15958848>{{Cite journal  | last1 = Hornick | first1 = JL. | last2 = Fletcher | first2 = CD. | title = Soft tissue perineurioma: clinicopathologic analysis of 81 cases including those with atypical histologic features. | journal = Am J Surg Pathol | volume = 29 | issue = 7 | pages = 845-58 | month = Jul | year = 2005 | doi =  | PMID = 15958848 }}</ref><ref name=pmid1497116>{{Cite journal  | last1 = Tsang | first1 = WY. | last2 = Chan | first2 = JK. | last3 = Chow | first3 = LT. | last4 = Tse | first4 = CC. | title = Perineurioma: an uncommon soft tissue neoplasm distinct from localized hypertrophic neuropathy and neurofibroma. | journal = Am J Surg Pathol | volume = 16 | issue = 8 | pages = 756-63 | month = Aug | year = 1992 | doi =  | PMID = 1497116 }}</ref>
*S100 -ve.
*EMA +ve.
*CD34 ~65% +ve.<ref name=pmid15958848/>


==Traumatic neuroma==
==Traumatic neuroma==

Latest revision as of 14:18, 29 August 2018

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]

Specific diagnoses

Schwannoma

Main article: Schwannoma

Perineurioma

Main article: Perineurioma

Traumatic neuroma

May be referred to as neuroma.
Main article: Traumatic neuroma

Palisaded encapsulated neuroma

  • Abbreviated PEN.
  • AKA palisaded and encapsulated neuroma.
  • AKA solitary circumscribed neuroma.

General

  • Flesh-colour papule - classically on the face.[2]
  • Isolated finding - not associated with a systemic disease or malignancy.[3]
  • Superficial skin papule.[4]
  • It is considered hyperplastic rather than neoplastic. [5]

Microscopic

Features:[2]

  • Encapsulated dermal spindle cell lesion.
    • Fasciular arrangement.
    • Neural-type spindle cells:
      1. Not vacuolated.
      2. Nuclei have pointy ends.
      3. Sometimes epitheloid appearance.
  • Intralesional clefts.
    • Useful to differentiate from schwannoma.

DDx:

  • Schwannoma:[2]
    • No intralesional clefts.
    • More variability in the cellularity.
    • May be deep.

Other considerations:

  • Leiomyoma - cytoplasm not vacuolated, nuclei more elliptical.

Images:

  • Palisaded and encapsulated neuroma (Ed Uthman)

  • PEN, S-100 staining (Ed Uthman)

Palisading/encapcuslated neuroma Palisading/encapcuslated neuroma
Palisading/encapsulated (Reed’s) neuroma. A. A dermal nodule shows an attenuated capsule (black arrows) about a fasciculated spindle cell lesion with artefactual clefts (green arrows). B. The bland spindled nuclei, amid clear cytoplasm with thin eosinophilic wisps, are often wavy (black arrows), with pointed ends (green arrows); leiomyomas have blunt ended nuclei and more eosinophilic cytoplasm. These benign neoplasms, unlike neurofibromas, lack an association with neurofibromatosis.

IHC

Features:[3]

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

Neurofibroma

Main article: Neurofibroma

Includes discussion of plexiform neurofibroma.

Neurothekeoma

Main article: Neurothekeoma

Malignant peripheral nerve sheath tumour

Main article: Malignant peripheral nerve sheath tumour

Malignant triton tumour

  • Abbreviated MTT.
  • AKA malignant peripheral nerve sheath tumor with rhabdomyosarcomatous differentiation.[6]

General

  • Rare.
  • Considered to be a variant of MPNST.
  • Prognosis worse that conventional MPNST.[6]
    • Five year survival ~14%.[7]
  • 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.[8]

Microscopic

Features - Woodruff criteria - all three required:[6]

  1. (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).
  2. Schwann cell tumour characteristics.
  3. Rhabdomyoblasts.
    • Eccentric nucleus.
    • Moderate amount of eosinophilic cytoplasm.
    • +/-Cross-striations.

DDx:

IHC

Features:

  • S100 +ve/-ve -- usu. focal if positive.[6]
  • Leu-7 +ve/-ve.
  • Myelin basic protein +ve/-ve.

Rhabdomyoblastic differentiation:[6]

  • Desmin.
  • Actin.
  • Myogenin.

EM

  • +/-Sarcomeres.[6]

Morton neuroma

AKA plantar interdigital neuroma.[9]
Main article: Morton neuroma

See also

References

  1. ↑ 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. ↑ 2.0 2.1 2.2 Busam, Klaus J. (2009). Dermatopathology: A Volume in the Foundations in Diagnostic Pathology Series (1st ed.). Saunders. pp. 536. ISBN 978-0443066542.
  3. ↑ 3.0 3.1 3.2 Newman, MD.; Milgraum, S. (2008). "Palisaded encapsulated neuroma (PEN): an often misdiagnosed neural tumor.". Dermatol Online J 14 (7): 12. PMID 18718196.
  4. ↑ S. Sade. 8 September 2011.
  5. ↑ Rosai & Ackermann, Surgical Pathology, 10th ed. p183
  6. ↑ 6.0 6.1 6.2 6.3 6.4 6.5 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.
  7. ↑ 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.
  8. ↑ 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.
  9. ↑ Makki, D.; Haddad, BZ.; Mahmood, Z.; Shahid, MS.; Pathak, S.; Garnham, I. (Sep 2012). "Efficacy of corticosteroid injection versus size of plantar interdigital neuroma.". Foot Ankle Int 33 (9): 722-6. doi:DOI: 10.3113/FAI.2012.0722. PMID 22995258.
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