# Colonic endometriosis: from subtotal bowel obstruction to malignant transformation - a case series and literature review

**Authors:** Roland Fejes, Zsófia Balajthy, Csaba Góg, Ágota Vajda, Fanni Hegedűs, Zsolt Simonka, Szabolcs Ábrahám

PMC · DOI: 10.1186/s12957-025-03888-x · 2025-06-11

## TL;DR

This paper presents two cases of colonic endometriosis, showing how it can cause bowel blockage or turn cancerous, and highlights the importance of accurate diagnosis and surgery.

## Contribution

The novelty lies in illustrating the clinical diversity and malignant potential of colonic endometriosis through case reports and emphasizing the need for histopathological confirmation.

## Key findings

- Colonic endometriosis can cause subtotal bowel obstruction, as seen in a case requiring laparoscopic resection.
- Endometriosis may transform into endometrioid adenocarcinoma, mimicking colorectal cancer and requiring histopathological analysis for accurate diagnosis.
- Laparoscopic surgery is effective for treating colonic endometriosis and its malignant transformation.

## Abstract

Colonic involvement due to endometriosis is a rare condition with a nonspecific clinical presentation. In rare instances, it may undergo malignant transformation, mimicking primary colorectal carcinoma and complicating clinical decision-making.

We present two cases illustrating the diverse clinical manifestations of colonic endometriosis. In Case 1, a female patient underwent appendectomy for abdominal pain, but further evaluation revealed full-thickness endometriosis of the sigmoid colon, causing subtotal occlusion. In Case 2, sigmoid endometriosis was discovered during endoscopic evaluation prompted by positive occult fecal blood testing. Histopathological analysis revealed malignant transformation to endometrioid adenocarcinoma. In both cases, definitive treatment was achieved via laparoscopic sigmoid resection, highlighting the role of laparoscopic surgery in managing such conditions.

The potential for malignant transformation of colonic endometriosis and its tendency to mimic colorectal carcinoma underscore the importance of proper tissue sampling methods and histopathological confirmation. A high index of suspicion and appropriate surgical intervention are key to effective management.

## Linked entities

- **Diseases:** endometriosis (MONDO:0005133), colorectal carcinoma (MONDO:0024331), endometrioid adenocarcinoma (MONDO:0005026)

## Full-text entities

- **Diseases:** Colonic endometriosis (MESH:D004715), colorectal carcinoma (MESH:D015179), abdominal pain (MESH:D015746), endometrioid adenocarcinoma (MESH:D018269), bowel obstruction (MESH:D012778)
- **Species:** Homo sapiens (human, species) [taxon 9606]

## Figures

7 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12153086/full.md

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Source: https://tomesphere.com/paper/PMC12153086