Difference between revisions of "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 [[Peripheral nerve sheath tumours#Schwannoma|schwannoma]].
'''Peripheral nerve sheath tumours''', abbreviated '''PNSTs''', are common in [[neuropathology]] and occasionally show-up elsewhere.  A very common PNST is the [[schwannoma]].


=Classification=
=Classification=
Line 16: Line 16:


==Perineurioma==
==Perineurioma==
===General===
{{Main|Perineurioma}}
*Benign tumour derived from perineurial cells.
 
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>
 
===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>
 
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 Perineuroma (conganat.org)].
 
===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==
===General===
:May be referred to as ''[[neuroma]]''.
*Consequence of trauma - diagnosis requires history of trauma.
{{Main|Traumatic neuroma}}
**May mimic a cancer recurrence at the site of a surgery.<ref name=pmid22330690/>
 
===Microscopic===
Features:<ref name=Ref_DCHH317>{{Ref DCHH|317}}</ref><ref name=pmid22330690/>
*+/-Nerve - that was injured.
*Grouping of disordered nerve fibre bundles in fibrous tissue (collagen) - '''key feature'''.
*+/-Myxoid change.
*+/-Axonal swellings (ovoid pink/purple blobs).
 
DDx:
*[[Morton neuroma]] (foot).
 
Images:
*[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3296625/figure/F2/ Traumatic neuroma (nih.gov)].<ref name=pmid22330690>{{Cite journal  | last1 = Li | first1 = Q. | last2 = Gao | first2 = EL. | last3 = Yang | first3 = YL. | last4 = Hu | first4 = HY. | last5 = Hu | first5 = XQ. | title = Traumatic neuroma in a patient with breast cancer after mastectomy: a case report and review of the literature. | journal = World J Surg Oncol | volume = 10 | issue =  | pages = 35 | month =  | year = 2012 | doi = 10.1186/1477-7819-10-35 | PMID = 22330690 }}</ref>
*[http://path.upmc.edu/cases/case502.html Traumatic neuroma - several images (upmc.edu)].
*[http://www.sarcomaimages.com/index.php?v=Neuroma,-Traumatic Traumatic neuroma (sarcomaimages.com)].
*[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2627419/figure/F1/ Traumatic neuroma (nih.gov)].<ref name=pmid17554193>{{Cite journal  | last1 = Kwon | first1 = JH. | last2 = Ryu | first2 = SW. | last3 = Kang | first3 = YN. | title = Traumatic neuroma around the celiac trunk after gastrectomy mimicking a nodal metastasis: a case report. | journal = Korean J Radiol | volume = 8 | issue = 3 | pages = 242-5 | month =  | year =  | doi =  | PMID = 17554193 | PMC = 2627419 }}</ref>
 
===Sign out===
<pre>
SOFT TISSUE LESION, RIGHT WRIST, EXCISION:
- TRAUMATIC NEUROMA.
- BENIGN FIBROADIPOSE TISSUE.
</pre>
 
====Micro====
The sections show disordered nerve fibre bundles in fibrous tissue.


==Palisaded encapsulated neuroma==
==Palisaded encapsulated neuroma==
*Abbreviated ''PEN''.
*Abbreviated ''PEN''.
*[[AKA]] ''palisaded and encapsulated neuroma''.
*[[AKA]] ''palisaded and encapsulated neuroma''.
*[[AKA]] ''solitary circumscribed neuroma''.
===General===
===General===
*Flesh-colour [[papule]] - classically on the face.<ref name=Ref_Derm536>{{Ref Derm|536}}</ref>
*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>
*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>
*Superficial skin.<ref>S. Sade. 8 September 2011.</ref>
*Superficial skin papule.<ref>S. Sade. 8 September 2011.</ref>
*It is considered hyperplastic rather than neoplastic. <ref>Rosai & Ackermann, Surgical Pathology, 10th ed. p183</ref>


===Microscopic===
===Microscopic===
Line 92: Line 40:
**#Not vacuolated.
**#Not vacuolated.
**#Nuclei have pointy ends.
**#Nuclei have pointy ends.
**#Sometimes epitheloid appearance.
*Intralesional clefts.
*Intralesional clefts.
**Useful to differentiate from schwannoma.
**Useful to differentiate from schwannoma.
Line 106: Line 55:
Images:
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>
*[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>
<gallery>
File:Palisaded_and_Encapsulated_Neuroma_(3952635881).jpg | Palisaded and encapsulated neuroma (Ed Uthman)
File:Palisaded_and_Encapsulated_Neuroma,_S-100_Immunostain_(3953412396).jpg| PEN, S-100 staining (Ed Uthman)
</gallery>
[[File:569 dp sl 1.png| Palisading/encapcuslated neuroma]]
[[File:569 dp sl 2.png| Palisading/encapcuslated neuroma]]<br>
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===
===IHC===
Line 113: Line 71:


==Neurofibroma==
==Neurofibroma==
:This section includes ''plexiform neurofibroma''.
{{Main|Neurofibroma}}
===General===
Includes discussion of ''plexiform neurofibroma''.
*May be a part of [[neurofibromatosis]] 1 (NF1).
*A [[painful skin lesion]].
*Composed of Schwann cells, axons, fibrous material.<ref name=pmid17893219/>
 
Classification:<ref name=pmid15486243>{{Cite journal  | last1 = Wilkinson | first1 = LM. | last2 = Manson | first2 = D. | last3 = Smith | first3 = CR. | title = Best cases from the AFIP: plexiform neurofibroma of the bladder. | journal = Radiographics | volume = 24 Suppl 1 | issue =  | pages = S237-42 | month = Oct | year = 2004 | doi = 10.1148/rg.24si035170 | PMID = 15486243 }}</ref>
#Localized - sporatic.
#Diffuse - usually poorly defined, young adults and children; sporatic.
#Plexiform - associated with NF1.
 
===Gross/radiologic===
Gross features (plexiform NF):<ref name=pmid15486243>{{Cite journal  | last1 = Wilkinson | first1 = LM. | last2 = Manson | first2 = D. | last3 = Smith | first3 = CR. | title = Best cases from the AFIP: plexiform neurofibroma of the bladder. | journal = Radiographics | volume = 24 Suppl 1 | issue =  | pages = S237-42 | month = Oct | year = 2004 | doi = 10.1148/rg.24si035170 | PMID = 15486243 }}</ref>
*"Bag of worms" appearance.
 
Radiologic:<ref name=pmid15486243/>
*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".<ref name=pmid17893219/>
**Multiple well-circumscribed nests.
*Mast cells<ref name=pmid20233971>{{Cite journal  | last1 = Staser | first1 = K. | last2 = Yang | first2 = FC. | last3 = Clapp | first3 = DW. | title = Mast cells and the neurofibroma microenvironment. | journal = Blood | volume = 116 | issue = 2 | pages = 157-64 | month = Jul | year = 2010 | doi = 10.1182/blood-2009-09-242875 | PMID = 20233971 }}</ref> - one has to look for them at high power.
**Very useful for confirming the low power suspicion.
 
DDx:
*[[Plexiform neurofibroma]].
*[[Schwannoma]].
*[[Dermatofibrosarcoma protuberans]] (DFSP) - S-100 -ve.
*[[Ganglioneuroma]].
*Neurotized [[melanocytic nevus]] -  melanocyte nests make the diagnosis, otherwise immunostains are needed to differentiate.<ref name=pmid693815>{{Cite journal  | last1 = Gray | first1 = MH. | last2 = Smoller | first2 = BR. | last3 = McNutt | first3 = NS. | last4 = Hsu | first4 = A. | title = Neurofibromas and neurotized melanocytic nevi are immunohistochemically distinct neoplasms. | journal = Am J Dermatopathol | volume = 12 | issue = 3 | pages = 234-41 | month = Jun | year = 1990 | doi =  | PMID = 1693815 }}</ref>
**Usually have more [[mast cell]]s than neurofibromas.<ref name=pmid8432898>{{Cite journal  | last1 = Carr | first1 = NJ. | last2 = Warren | first2 = AY. | title = Mast cell numbers in melanocytic naevi and cutaneous neurofibromas. | journal = J Clin Pathol | volume = 46 | issue = 1 | pages = 86-7 | month = Jan | year = 1993 | doi =  | PMID = 8432898 }}</ref>
 
====Images====
<gallery>
Image:Neurofibroma_(1).jpg | Neurofibroma - low mag. (WC)
Image:Neurofibroma_(2).jpg | Neurofibroma - intermed. mag. (WC)
Image:Neurofibroma_(3).jpg | Neurofibroma - high mag. (WC)
</gallery>
www:
*[http://radiographics.rsna.org/content/24/suppl_1/S237/F9.expansion.html Plexiform neurofibroma (rsna.org)].
*[http://radiographics.rsna.org/content/24/suppl_1/S237/F10.expansion.html Plexiform neurofibroma (rsna.org)].
*[http://path.upmc.edu/cases/case304/micro.html Plexiform neurofibroma - several images (upmc.edu)].
*[http://eyewiki.aao.org/File:Orbital_Neurofibroma_-_S100.JPG Neurofibroma - S-100 (eyewiki.aao.org)].
 
===IHC===
Features:<ref name=pmid12692193>{{cite journal |author=Hirose T, Tani T, Shimada T, Ishizawa K, Shimada S, Sano T |title=Immunohistochemical demonstration of EMA/Glut1-positive perineurial cells and CD34-positive fibroblastic cells in peripheral nerve sheath tumors |journal=Mod. Pathol. |volume=16 |issue=4 |pages=293–8 |year=2003 |month=April |pmid=12692193 |doi=10.1097/01.MP.0000062654.83617.B7 |url=http://www.nature.com/modpathol/journal/v16/n4/full/3880761a.html }}</ref>
*S100 +ve -- wavy pattern.<ref name=pmid22742554>{{Cite journal  | last1 = Chen | first1 = Y. | last2 = Klonowski | first2 = PW. | last3 = Lind | first3 = AC. | last4 = Lu | first4 = D. | title = Differentiating neurotized melanocytic nevi from neurofibromas using Melan-A (MART-1) immunohistochemical stain. | journal = Arch Pathol Lab Med | volume = 136 | issue = 7 | pages = 810-5 | month = Jul | year = 2012 | doi = 10.5858/arpa.2011-0335-OA | PMID = 22742554 }}
</ref>
*CD34 +ve.
*Glut1 +ve.
*EMA +ve/-ve.
*NF +ve/-ve.<ref name=pmid22742554/>
*MART-1 -ve.<ref name=pmid22742554/>
**Positive in neurotized melanocytic nevi.
 
===Sign out===
<pre>
FOURTH TOE, LEFT, EXCISION:
- NEUROFIBROMA.
</pre>
 
====Micro====
The sections show skin with a lesion composed of irregular-shaped groups of bland dermal spindle cells with wavy nuclei and pale-eosinophilic cytoplasm. Mast cells are seen scattered throughout the lesion. Thick collagen separates the clusters of the spindle
cells. There is no nuclear atypia. Mitotic activity is not appreciated. No melanocytic nests are identified.
 
The overlying epidermis matures to the surface.
 
=====Alternate=====
The sections show skin with an unencapsulated dermal spindle cell lesion with navy nuclei that have a likeness to shredded carrots. Occasional mast cells are present within the lesion. There is no nuclear atypia. Mitotic activity is not appreciated. No melanocytic nests are identified.


==Neurothekeoma==
==Neurothekeoma==
*[[AKA]] ''myxoma of the nerve sheath'', [[AKA]] ''nerve sheath myxoma''.
{{Main|Neurothekeoma}}
===General===
*Rare.
*Female > male.
 
===Microscopic===
Features:<ref name=pmid17325474>{{cite journal |author=Hornick JL, Fletcher CD |title=Cellular neurothekeoma: detailed characterization in a series of 133 cases |journal=Am. J. Surg. Pathol. |volume=31 |issue=3 |pages=329–40 |year=2007 |month=March |pmid=17325474 |doi=10.1097/01.pas.0000213360.03133.89 |url=}}</ref>
*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.
 
Notes:
*No atypia.
*Mitoses rare/none.
*Often poorly circumscribed.
 
Subtypes:<ref name=pmid10555009>{{cite journal |author=Wang AR, May D, Bourne P, Scott G |title=PGP9.5: a marker for cellular neurothekeoma |journal=Am. J. Surg. Pathol. |volume=23 |issue=11 |pages=1401–7 |year=1999 |month=November |pmid=10555009 |doi= |url=}}</ref>
*Cellular.
*[[Myxoid]].
*Intermediate.
 
DDx:
*[[Dermatofibroma]].
*[[Angiomatoid fibrous histiocytoma]] -- have cystic blood filled spaces, inflammation.<ref>URL: [http://surgpathcriteria.stanford.edu/softfib/angiomatoid_fibrous_histiocytoma/ http://surgpathcriteria.stanford.edu/softfib/angiomatoid_fibrous_histiocytoma/]. Accessed on: 11 May 2011.</ref>
 
Images:
*[http://en.wikipedia.org/wiki/File:Neurothekeoma2.JPG Neurothekeoma (WP)].
*[http://path.upmc.edu/cases/case586.html Neurothekeoma - several images (upmc.edu)].
 
===IHC===
Features:<ref name=pmid17325474/>
*NKI/C3 ([[AKA]] NKI-C3) +ve.
*NSE +/-ve.
 
Others:<ref name=pmid17592278>{{cite journal |author=Fetsch JF, Laskin WB, Hallman JR, Lupton GP, Miettinen M |title=Neurothekeoma: an analysis of 178 tumors with detailed immunohistochemical data and long-term patient follow-up information |journal=Am. J. Surg. Pathol. |volume=31 |issue=7 |pages=1103–14 |year=2007 |month=July |pmid=17592278 |doi=10.1097/PAS.0b013e31802d96af |url=}}</ref>
*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==
==Malignant peripheral nerve sheath tumour==
Line 286: Line 125:


==Morton neuroma==
==Morton neuroma==
===General===
:[[AKA]] ''plantar interdigital neuroma''.<ref name=pmid22995258>{{Cite journal  | last1 = Makki | first1 = D. | last2 = Haddad | first2 = BZ. | last3 = Mahmood | first3 = Z. | last4 = Shahid | first4 = MS. | last5 = Pathak | first5 = S. | last6 = Garnham | first6 = I. | title = Efficacy of corticosteroid injection versus size of plantar interdigital neuroma. | journal = Foot Ankle Int | volume = 33 | issue = 9 | pages = 722-6 | month = Sep | year = 2012 | doi = DOI: 10.3113/FAI.2012.0722 | PMID = 22995258 }}</ref>
*Benign foot condition.
{{Main|Morton neuroma}}
*Uncommon.
*Usu. interdigital nerves.
 
Etiology:
*Indirect nerve trauma.
 
Clinical:<ref name=Ref_Sternberg4>{{Ref Sternberg4|243}}</ref>
*Foot pain.
 
===Microscopic===
Features:<ref name=Ref_Sternberg4>{{Ref Sternberg4|243}}</ref>
*Extensive fibrosis around and within the nerve.
*Digital artery:
**+/-[[Thrombosis]].
**+/-Arterial thickening.
 
DDx:
*[[Traumatic neuroma]].
 
Images:
*[http://www.tumorlibrary.com/case/detail.jsp?image_id=2324 Morton neuroma (tumorlibrary.com)].
*[http://ars.els-cdn.com/content/image/1-s2.0-S1027811711000863-gr1.jpg Perineural fibrosis (els-cdn.com)].<ref>URL: [http://www.sciencedirect.com/science/article/pii/S1027811711000863 http://www.sciencedirect.com/science/article/pii/S1027811711000863]. Accessed on: 27 December 2012.</ref>


=See also=
=See also=

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

Perineurioma

Traumatic neuroma

May be referred to as 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:

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

Includes discussion of plexiform neurofibroma.

Neurothekeoma

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]

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.