Colon tumor
Mesenchymal tumors

Topic Completed: 1 August 2017

Revised: 15 January 2019, last major update August 2017

Copyright: (c) 2003-2017,, Inc.

PubMed search: colonic schwannoma

Page views in 2018: 921
Page views in 2019 to date: 546
Cite this page: Gonzalez R. Schwannoma. website. Accessed May 21st, 2019.
Definition / general
  • Uncommon mesenchymal tumor of colon
Essential features
  • Benign spindle cell lesion of muscularis propria with prominent lymphoid cuff
  • Positive for S100, unlike gastrointestinal stromal tumor (GIST)
  • No syndromic association
  • GANT is an outdated term for GIST, not schwannoma
  • Rare; less common than colonic GIST
  • Colon is second most common site in gastrointestinal tract for schwannoma, after stomach
Clinical features
Case reports
Clinical images

Images hosted on other servers:

Submucosal colonic tumors

Gross description
  • Well circumscribed but usually not encapsulated
  • Polypoid intraluminal mass with mucosal ulceration, usually in right colon
Gross images

Images hosted on other servers:

Various images

Microscopic (histologic) description
  • Nonencapsulated, polypoid lesion arising in muscularis propria (Mod Pathol 2015;28 Suppl 1:S47)
  • Bland spindle cells with elongated, pointed nuclei; no or indistinct Verocay bodies and no prominent nuclear palisading
  • Stroma may be myxoid and contain prominent collagen bands
  • Surrounded by lymphoid cuff
  • May have microcystic or reticular features (Am J Surg Pathol 2008;32:1080) or may be epithelioid
  • May have focal nuclear atypia; mitotic figures rare
  • Usually no vascular hyalinization or xanthoma cells
Microscopic (histologic) images

Images hosted on PathOut server

H&E, contributed by Dr. Raul Gonzalez, University of Rochester Medical Center (USA)

Images hosted on other servers:

Various images

Various immunostains

Positive stains
Negative stains
Differential diagnosis
Board review question #1
Which of the following is a common feature of gastrointestinal schwannomas?

A. Artifactual cytoplasmic vacuoles
B. Dense cellularity and high mitotic rate
C. Epicenter in the muscularis mucosae
D. Peripheral lymphoid cuff
E. Verocay bodies and thick walled vasculature
Board review answer #1
D. Peripheral lymphoid cuff
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