A Case of Uterine Adenosarcoma and Colonic Endometriosis Masquerading as Inflammatory Bowel Disease

Background Endometriosis is a prevalent gynecological condition that primarily affects women of reproductive age. When thegastrointestinal system is involved, it can lead to bowel dysfunction and pose diagnostic challenges. Aims To present a rare case of gastrointestinal endometriosis with concurrent uterine adenosarcoma, highlighting thediag- nostic complexities and therapeutic considerations.

A 42-year-old female presented with refractory bloody diarrhea, abdominal pain, and significant unintentional weightloss for several months. Initial investigations, including stool studies and inflammatory markers, ruled out infectiousand common inflammatory causes. Endoscopic evaluation revealed multiple polypoid lesions, prompting furtherimaging. Mag- netic resonance enterography (MRE) identified a uterine mass with suspected extrauterine involvementand a rectal nodule, raising concerns for malignancy or extensive gastrointestinal endometriosis. The patientunderwent surgical management, including total hysterectomy, bilateral salpingo-oophorectomy, and lower anteriorresection.

Histopathological analysis confirmed the coexistence of uterine adenosarcoma and rectal endometriosis. The patient- fully recovered after surgery without complications. At her 12-month follow-up, she remained asymptomatic, with noevidence of recurrence or residual disease.

This case underscores the diagnostic and therapeutic challenges of gastrointestinal endometriosis, particularly in thepresence of coexisting malignancy. A multidisciplinary approach is essential for early recognition and promptinterven- tion, which are crucial for improving patient outcomes and quality of life.

Rectum · Inflammatory disease · Adenomyosis · Neoplasms Extended author information available on the last page of the article 2230 Digestive Diseases and Sciences (2025) 70:2229–2232 Fig. 1 Magnetic resonance enterography findings. A Axial half-Fourier acquisition single- shot turbo spin-echo (HASTE) image shows ill-defined T2-hypointensity lesions of the uterus, suggestive of adeno- myosis (white arrowheads). At the posterior aspect of uterus, there is a large irregular mass with heterogeneous T2-hyperin- tensity (arrows), suspicious for malignancy. In addition, there is a T2-hypointense submucosal nodule (2.3 cm in size) at the anterior wall of the rectum, sug- gestive of endometriosis (black arrowhead). B Coronal HASTE image shows the irregular T2-hyperintense uterine mass (arrows). C Axial diffusion- weighted image shows focal high signal intensity of the mass (arrow), suggestive of increased cellularity. D Axial post-con- trast T1-weighted image shows heterogeneous enhancement of the uterine mass (arrows) with focal non-enhancing necrotic areas. The rectal nodule (arrow- head) shows mild enhancement Fig. 2 Operative findings and the excised specimen. A On entry of abdomen, severe adhesion of descending colon on posterior uterine wall noted. The uterine corpus showed extensive adenomyosis. B Rectal endometriosis with full penetration into the mucosa 2231Digestive Diseases and Sciences (2025) 70:2229–2232 A 42-year-old woman presented with a month-long history of mucoid bloody diarrhea, weight loss, and worsening bowel symptoms. Despite empirical treatment, her condition deteriorated, prompting further evaluation. Initial tests ruled out infections, and colonoscopy showed no active inflam- mation. However, magnetic resonance enterography (MRE) revealed an 8 cm uterine mass suspicious for malignancy and a rectal nodule suggesting endometriosis [1, 2] (Fig.  1). Elevated CA-125 and CA19-9 supported these findings. She underwent hysterectomy, bilateral salpingo-oophorectomy, and rectal tumor resection (Fig.  2). Pathology confirmed uterine adenosarcoma (FIGO stage I) [3 ] and rectal endo- metriosis (Fig.  3). Post-surgery, she remained disease-free for 12 months, with complete resolution of symptoms. Author Contributions Conceptualization, data curation, formal analy- sis, methodology: Lin CJ. Project administration: Wei SC. Resources: Tai YJ, Chiang YC, Su TH, Shih IL, Kuo KT, Wei SC. Supervision: Kuo KT, Wei SC. Visualization: Tai YJ, Chiang YC, Su TH. Writing— original draft: Lin CJ, Tai YJ. Writing—review & editing: all authors. Approval of final manuscript: all authors. Funding The authors received no financial support for the research, authorship, and/or publication of this article. Data Availability No datasets were generated or analyzed during the current study. Declarations Conflict of interest The authors declare no competing interests. Fig. 3 Representative images of H&E, IHC staining and FISH analysis in surgical specimens. A The uterus exhibited extensive adenomyosis with endometrial glands and stroma surrounded by hypertrophic smooth muscle cells. B In adenomyosis without atypi- cal changes (B1), stromal cells showed focal p16 (B2) but no CDK4 protein expression (B3). Foci of atypical stromal cells with pleomor - phic hyperchromatic nuclei arise in and spreading along adenomyosis (B4). These atypical stromal cells are diffusely positive for p16 (B5) and CDK4 (B6) expression. C Evident necrosis in atypical stromal cells with focally but strongly MDM2 protein expression (C1, C2). Fluorescent in  situ hybridization showed MDM2 and CDK4 ampli- fication consistent with the diagnosis of adenosarcoma (C3: MDM2- red signals, CEP12-green signals, C4: 3' DDIT3-orange signals, 5' DDIT3-green signals). D Endometriosis in rectal tumor (inset figure) comprised bland-appearing stromal cells (H&E) 2232 Digestive Diseases and Sciences (2025) 70:2229–2232 Open Access This article is licensed under a Creative Commons Attri- bution-NonCommercial 4.0 International License, which permits any non-commercial use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Com- mons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regula- tion or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by-nc/4.0/.

1. Radzynski L, Boyer L, Kossai M, et al. Pictorial essay: MRI evalu- ation of endometriosis-associated neoplasms. Insights Imaging . 2023;14:144. 2. Fiorillo M, Neri B, Mancone R, et al. Inflammatory bowel dis- ease and endometriosis: diagnosis and clinical characteristics. Biomedicines. 2024;12:2521. 3. Mbatani N, Olawaiye AB, Prat J. Uterine sarcomas. Int J Gynaecol Obstet. 2018;143:51–58. Publisher's Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. Authors and Affiliations Chia‑Jou Lin1 · Ying‑Cheng Chiang1 · Tung‑Hung Su2,3 · I‑Lun Shih4 · Kuan‐Ting Kuo5 · Shu‑Chen Wei2 · Yi‑Jou Tai1 * Yi-Jou Tai [email protected] 1 Department of Obstetrics and Gynecology, College of Medicine, National Taiwan University, Taipei, Taiwan 2 Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan 3 Hepatitis Research Center, National Taiwan University Hospital, Taipei, Taiwan 4 Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan 5 Department of Pathology, National Taiwan University Hospital, Taipei, Taiwan