Colon tumor
Mesenchymal tumors
Perineurioma

Author: Raul S. Gonzalez, M.D. (see Authors page)

Revised: 28 June 2016, last major update June 2016

Copyright: (c) 2003-2016, PathologyOutlines.com, Inc.

PubMed Search: Colon tumor perineurioma
Definition / General
  • Benign polypoid lesion occurring in the colonic mucosa or submucosa
  • Peripheral nerve sheath tumor, often with overlying serrated/hyperplastic epithelium
Essential Features
  • Uncommon mucosal epithelial-mesenchymal lesion of the colon
  • Usually occurs in middle aged women
  • Benign, does not recur
Terminology
Sites
  • Usually in distal colon; rarely in small intestine
Clinical Features
Treatment
  • Excision (benign behavior)
Gross Description
  • Small sessile polyp (median size 0.4 cm)
Micro Description
  • Poorly circumscribed spindle cell proliferation, usually confined to the mucosa, with ovoid nuclei and pale indistinct cytoplasm, in a background of fine collagenous stroma
  • No atypia, no pleomorphism, no mitotic figures
  • Entrapped/overlying colonic crypts appear hyperplastic or serrated in the majority of cases
  • Perineurial proliferation sometimes focally present in otherwise typical sessile serrated polyp/adenoma (Am J Surg Pathol 2011;35:1373)
Micro Images

Images hosted on Pathout server:

Contributed by: Raul S. Gonzalez, M.D., University of Rochester Medical Center (USA)



Images hosted on other servers:
Missing Image

H&E showing uniform spindle cells

Missing Image

H&E demonstrating
epithelial and mesenchymal
components


Missing Image

Claudin1+

Missing Image

Perineal tumor:
H&E and EMA

Positive Stains
Electron Microscopy Description
  • Long bipolar cytoplasmic processes, prominent pinocytotic vesicles
Molecular / Cytogenetics Description
Differential Diagnosis