Colon
Mesenchymal tumors
Mucosal Schwann cell hamartoma


Topic Completed: 2 February 2021

Minor changes: 2 February 2021

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PubMed Search: Mucosal Schwann cell hamartoma

Raul S. Gonzalez, M.D.
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Cite this page: Gonzalez RS. Mucosal Schwann cell hamartoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/colontumormucosalschwann.html. Accessed March 4th, 2021.
Definition / general
  • Benign mucosal proliferation composed of Schwann cells
Essential features
  • Benign, incidental spindle cell lesion
  • Not associated with any clinical syndrome
  • Positive for S100, negative for EMA
Terminology
  • Has been called neuroma or neurofibroma in past
Sites
  • Can arise anywhere in the colorectum but more common distally
Clinical features
  • Average patient age is 62 years, with a female predominance (Am J Surg Pathol 2009;33:781)
  • Not associated with any particular syndrome
  • Lesions do not recur
Diagnosis
  • Discovered incidentally during colonoscopy
Case reports
Clinical images

Images hosted on other servers:

Rectal polyps on colonoscopy

Gross description
  • Small (6 mm or less) sessile polyp
Microscopic (histologic) description
  • Poorly circumscribed mucosal proliferation of spindle cells, with no whorling, no palisading, no fasciculation
  • Nuclei are generally small, bland and elongated
Microscopic (histologic) images

Contributed by Raul S. Gonzalez, M.D.

Lesion confined to mucosa

Bland nuclei with occasional enlargements

S100+



Images hosted on other servers:

Low power view of hematoxylin and eosin

S100 positivity

Histologic findings
of mucosal
Schwann cell
hamartomas

Positive stains
Sample pathology report
  • Transverse colon, polypectomy:
    • Mucosal Schwann cell hamartoma (see comment)
    • Comment: An immunohistochemical stain for S100 is positive.
Differential diagnosis
Board review style question #1

Which of the following is true about mucosal Schwann cell hamartoma of the colon?

  1. It demonstrates loss of nuclear H3K27me3 staining
  2. It is associated with neurofibromatosis
  3. It is usually > 1 cm
  4. It is usually discovered incidentally
Board review style answer #1
D. It is usually discovered incidentally

Comment Here

Reference: Mucosal Schwann cell hamartoma
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