Colon tumor
Mesenchymal tumors
Schwannoma

Author: Charanjeet Singh, M.D. (see Authors page)

Revised: 4 January 2017, last major update May 2012

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

PubMed search: colonic schwannoma

Cite this page: Schwannoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/colontumorschwannoma.html. Accessed February 22nd, 2017.
Definition / General
  • Rare; less common than colonic GIST
  • Median age 65 years, range 18 - 87 years; affects men and women equally
  • Benign behavior; not associated with neurofibromatosis
Case Reports
Clinical Images

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Submucosal colonic tumors

Gross Description
  • Well circumscribed but usually not encapsulated, polypoid intraluminal mass 0.5 to 5.5 cm with mucosal ulceration, usually in right colon
Gross Images

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Various images

Micro Description
  • In soft tissue, encapsulated biphasic nerve sheath tumor derived from Schwann cells with highly ordered cellular component (Antoni A) that palisades (Verocay bodies), plus myxoid component (Antoni B)
  • In colon, usually no encapsulated, no / indistinct Verocay bodies, no prominent nuclear palisading (Am J Surg Pathol 2001;25:846)
  • Usually trabecular pattern of spindle cells, surrounded by lymphoid cuff
  • May have epithelioid or plexiform features
  • Often focal nuclear atypia; 0 - 4 mitotic figures / 50 HPF
  • Usually no vascular hyalinization, no xanthoma cells
Micro Images

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Various images


Various immunostains

Positive Stains
Negative Stains
Differential Diagnosis
  • GIST: CD117+, CD34+, S100-, no prominent lymphoid infiltration and no microtrabecular pattern
  • Inflammatory myofibroblastic tumor: spindle cells with abundant amphophilic cytoplasm
  • Leiomyoma: rare, usually small polyps and positive for smooth muscle markers