# Colonic Ganglioneuroma—A Rare Finding During Colonoscopy

## TL;DR

A rare case of colonic ganglioneuroma was found in a 66-year-old woman during a colonoscopy, highlighting the importance of recognizing such benign tumors in the colon.

## Contribution

This case report adds to the limited literature on colonic ganglioneuromas and their potential associations with hereditary syndromes.

## Key findings

- A 3 mm sessile polyp in the ascending colon was diagnosed as a colonic ganglioneuroma.
- The lesion showed monomorphic spindle-cell proliferation and ganglion cells positive for Calretinin and S100.
- Colonic ganglioneuromas are mostly asymptomatic but can be linked to hereditary conditions like neurofibromatosis type 1.

## Abstract

A 66-year-old female underwent a colonoscopy for persistent left lower abdominal discomfort and mucous stool passage. Endoscopic examination revealed a 3 mm sessile polyp in the ascending colon. Histopathological examination of the polyp showed preserved crypt architecture with a monomorphic spindle-cell proliferation within the lamina propria. Scattered ganglion cells were present and demonstrated immunoreactivity for Calretinin and S100. The lesion was diagnosed as a colonic ganglioneuroma. Ganglioneuromas are rarely localised to the gastrointestinal tract and often detected incidentally during colonoscopic screening. While solitary lesions are typically sporadic; diffuse or multiple ganglioneuromas may be associated with hereditary syndromes such as neurofibromatosis type 1, multiple endocrine neoplasia type 2B, and juvenile polyposis, the latter belonging to the PTEN-hamartoma tumour syndrome spectrum. Clinically, most colonic ganglioneuromas are asymptomatic, although some may present with nonspecific gastrointestinal symptoms. Despite their benign nature, rare cases of malignant transformation and association with adenocarcinoma have been reported.