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

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.