Colon (tumor & nontumor)
Mesenchymal tumors
Mucosal Schwann cell hamartoma
Author: Raul S. Gonzalez, M.D.
Topic Completed: 1 June 2016
Minor changes: 31 July 2020
Copyright: 2002-2019, PathologyOutlines.com, Inc.
PubMed Search: Mucosal Schwann cell hamartoma
Table of Contents
Definition / general | Essential features | Terminology | Sites | Clinical features | Diagnosis | Case reports | Clinical images | Gross description | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Negative stains | Differential diagnosis | Additional referencesCite this page: Gonzalez R. Mucosal Schwann cell hamartoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/colontumormucosalschwann.html. Accessed August 15th, 2020.
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
- 20 year old man with multiple colonic lesions (BMC Gastroenterol 2015;15:128)
- 59 year old man with ulcerative colitis (Gastroenterol Hepatol (N Y) 2013;9:183)
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 Gonzalez, M.D.
Various images
Images hosted on other servers:
Low power view on H&E
S100 positivity
Two rectal lesions (H&E and S100)
Positive stains
- S100 (lesional cells)
- Neurofilament / NFP (rare intralesional axons)
Negative stains
Differential diagnosis
- Perineurioma: positive for EMA, negative for S100
- Ganglioneuroma: ganglion cells present
- Neurofibroma: unlikely to involve mucosa
- Benign epithelioid peripheral nerve sheath tumor: cells are epithelioid; lesion extends into superficial submucosa (Am J Surg Pathol 2005;29:1310)
- Tactile corpuscle-like body: usually small, incidental finding in mucosal biopsy (Am J Surg Pathol 2015;39:1668)
Additional references
