# Endometriosis-Associated Intestinal Tumor: A Case Report and Literature Review with Comprehensive Proteomic Data

**Authors:** Naoyuki Toyota, Yuki Yoshimatsu, Chihiro Kamozawa, Ryo Nakanishi, Shin Fujita, Makoto Abe, Ryo Konno, Yusuke Kawashima, Tadashi Kondo

PMC · DOI: 10.70352/scrj.cr.25-0761 · Surgical Case Reports · 2026-03-11

## TL;DR

This case report describes a rare intestinal tumor linked to endometriosis and highlights the challenges in diagnosis and treatment.

## Contribution

The paper provides comprehensive proteomic data from an endometriosis-associated intestinal tumor, offering insights for future research.

## Key findings

- The patient was diagnosed with endometriosis-associated endometrioid adenocarcinoma after inconclusive initial tests.
- Proteomic profiling of the tumor may aid in understanding its biology and guide future translational research.
- The patient remained disease-free for 3.5 years following surgery and chemotherapy.

## Abstract

Endometriosis-associated intestinal tumors (EAITs) are rare malignancies that arise from ectopic endometrial tissue, and their clinical and molecular characteristics remain poorly defined.

We report a 53-year-old woman who presented with rectal bleeding. Imaging revealed a rectal mass invading the uterus. An initial endoscopic biopsy was inconclusive; however, a subsequent CT-guided biopsy confirmed adenocarcinoma. Immunohistochemical analysis suggested a gynecological origin. The patient underwent posterior total pelvic exenteration with bilateral lymphadenectomy. Histopathological evaluation confirmed endometriosis-associated endometrioid adenocarcinoma with ovarian metastasis. Postoperative chemotherapy was administered, and the patient has remained disease-free for 3.5 years.

This case highlights the diagnostic challenges and clinical complexity of EAITs. Tumor proteomic profiling provided additional biological insights and may serve as a reference for future comparative and translational research.

## Linked entities

- **Diseases:** endometriosis (MONDO:0005133), adenocarcinoma (MONDO:0004970)

## Full-text entities

- **Diseases:** Endometriosis (MESH:D004715), adenocarcinoma (MESH:D000230), EAITs (MESH:D007414), endometrioid adenocarcinoma (MESH:D018269), ovarian metastasis (MESH:D010049), Tumor (MESH:D009369), rectal bleeding (MESH:D012002)
- **Species:** Homo sapiens (human, species) [taxon 9606]

## Full text

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## Figures

3 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12991934/full.md

## References

44 references — full list in the complete paper: https://tomesphere.com/paper/PMC12991934/full.md

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Source: https://tomesphere.com/paper/PMC12991934