{"paper_id":"12d54224-d965-4c8f-a57c-ebeebc42e88e","body_text":"Open Access                                                                 Original Research Article                                            \n \nMedPeer Publisher \nAbbreviated Key Title: MedPeer \nISSN : 3066-2737 \nhomepage: https://www.medpeerpublishers.com \n \n \n \nNormal Endoscopy Does Not Exclude Rectosigmoid \nEndometriosis: A Diagnostic Pitfall Revealed by \nEndoscopic Ultrasonography \n \n \n \nDOI: 10.70780/medpeer.000QGSR \n \nAUTHORS AND AFFILIATION  \nSara HDIYE ˡ, Ahlame BENHAMDANE ˡ, Tarik ADDAJOU ˡ, Fedoua ROUIBAA ˡ, \nHassan SEDDIK ˡ \nˡ Department of Digestive Endoscopy, Mohammed V Military Hospital, Rabat, Morocco \nCorresponding author: Sara HDIYE .  \n \nABSTRACT \n \nIntestinal involvement in deep infiltrating endometriosis predominantly affects the \nrectosigmoid colon and may remain difficult to diagnose because mucosal abnormalities are \noften absent. We report the case of a 39-year-old woman with a history of diffuse \nendometriosis who presented with pelvic pain associated with cyclic rectal discharge. Pelvic \nmagnetic resonance imaging suggested infiltration of the rectosigmoid junction. \nRectosigmoidoscopy showed no visible abnormality. Radial rectal endoscopic \nultrasonography subsequently demonstrated infiltration of the anterior sigmoid wall \nextending from 15 to 23 cm from the anal verge, involving the muscular layer while \npreserving the mucosa and the remaining rectal wall structures. Sigmoid endometriosis was \ndiagnosed, and the patient was referred for multidisciplinary management. This case \nemphasizes the importance of endoscopic ultrasonography in the evaluation of suspected \nbowel endometriosis when conventional endoscopy is inconclusive. \n  \nKEYWORDS :  \n \nEndometriosis, MRI, endoscopic ultrasound, case report \n \n \n \n \n\n    Open Access                                                                 Original Research Article                                            \n \nMAIN ARTICLE \nINTRODUCTION \nEndometriosis is a chronic estrogen-dependent condition characterized by the presence of \nendometrial-like tissue outside the uterine cavity. Deep infiltrating forms may involve pelvic \norgans, including the gastrointestinal tract, most commonly the rectosigmoid colon.  \nDigestive involvement can manifest with nonspecific symptoms such as pelvic pain, \ndyschezia, bowel habit changes, and cyclic rectal bleeding. [1] \nBecause intestinal lesions typically develop from the serosal surface and infiltrate the \nmuscular layer while sparing the mucosa, conventional endoscopic evaluation may be normal \ndespite significant disease. [2] \nImaging modalities such as pelvic magnetic resonance imaging and endoscopic \nultrasonography are therefore essential for evaluating bowel involvement and defining the \ndepth of infiltration. [2,3] \nThis case report describes a patient with cyclic rectal symptoms and rectosigmoid \nendometriosis diagnosed using endoscopic ultrasonography despite a normal \nrectosigmoidoscopy.  \n \nCASE REPORT :  \nA 39-year-old woman, followed for diffuse Endometriosis for the past two years, presented \nwith pelvic pain associated with cyclic rectal discharge. \nPelvic MRI demonstrated infiltration of the rectosigmoid junction suggestive of digestive \ninvolvement by endometriosis. Rectosigmoidoscopy was subsequently performed and \nshowed no mucosal abnormalities (Figure 1) \nComplementary radial rectal endoscopic ultrasonography revealed infiltration of the anterior \nwall of the sigmoid colon extending from 15 to 23 cm from the anal verge, originating from a \npelvic endometriotic focus. The lesion involved the sigmoid muscularis propria (Figures 2,3) \nwhile sparing the mucosa. The internal sphincter, external sphincter, and the muscularis \npropria of the remaining rectal segments were preserved (Figure 4). \nA diagnosis of sigmoid endometriosis was established, and the patient was referred to the \ngynecology department for further multidisciplinary management. \n \n \n \n\n    Open Access                                                                 Original Research Article                                            \n \nDISCUSSION  \nBowel involvement in Endometriosis represents a frequent but often underdiagnosed \nmanifestation of deep infiltrating disease, with a predilection for the rectosigmoid junction. \nThis localization is clinically relevant because it is associated with significant digestive and \npelvic symptoms, often leading to delayed diagnosis. [1] \nPatients may present with cyclical symptoms such as pelvic pain, dyschezia, constipation, or \nrectal bleeding, reflecting hormonal responsiveness of ectopic endometrial tissue. However, \nsymptom specificity remains limited, and clinical presentation may overlap with other \ngastrointestinal or gynecologic disorders, contributing to diagnostic delay. [1] \nA major diagnostic challenge lies in the typical pathophysiological pattern of bowel \nendometriosis, which begins at the serosal surface and progressively infiltrates the muscularis \npropria. Because mucosal involvement is rare, conventional endoscopic evaluation including \ncolonoscopy or rectosigmoidoscopy is often normal even in advanced disease.[2] \nThis explains the discordance observed in the present case between a normal \nrectosigmoidoscopy and imaging evidence of sigmoid wall infiltration. \nPelvic MRI is widely considered a key first-line imaging modality for mapping deep \ninfiltrating endometriosis and assessing pelvic organ involvement. It provides valuable \ninformation regarding lesion location, extension, and relationship with adjacent pelvic \nstructures, which is essential for preoperative planning. However, MRI may have limitations \nin accurately defining bowel wall layer involvement, particularly in distinguishing muscular \nfrom serosal infiltration. [3] \nEndoscopic ultrasonography complements MRI by providing high-resolution, layer-by-layer \nvisualization of the bowel wall. Its typical finding in bowel endometriosis is a hypoechoic \nlesion involving the muscularis propria with preservation of the mucosal layer, which is \nconsidered highly suggestive of deep infiltrating disease. [2] \nIn addition, endoscopic ultrasonography allows precise characterization of lesion extent, \ncircumferential involvement, and distance from the anal verge, which are critical parameters \nfor therapeutic decision-making. [3] \nBeyond diagnosis, endoscopic ultrasonography also plays a role in differential diagnosis, \nhelping to distinguish endometriosis from other infiltrative bowel diseases such as \nmalignancy or inflammatory bowel disease. [2] \nThe growing role of advanced endoscopic ultrasonography techniques, including fine-needle \naspiration, further expands its diagnostic potential by allowing histological confirmation in \nselected complex cases. [4] \n\n    Open Access                                                                 Original Research Article                                            \n \nOverall, optimal management of bowel endometriosis requires a multidisciplinary approach \nintegrating gynecology, gastroenterology, radiology, and colorectal surgery to tailor treatment \nstrategies according to symptom severity and disease extent.[1] \n \nCONCLUSION \nRectosigmoid involvement in deep infiltrating endometriosis should be suspected in patients \npresenting with cyclic rectal symptoms even when conventional endoscopy is normal. This \ncase emphasizes the pivotal role of endoscopic ultrasonography in detecting muscular \ninfiltration and guiding diagnosis and management \n \nFIGURES :  \n \n \n \n \nFigure 1 : Normal rectosigmoid colon on endoscopy \n \nFigure 2 : endoscopic ultrasound image showing sigmoid muscularis  (Orange arrow) and \nhourglass-shaped endometriosis (Red arrow)  \n \n \n\n\n    Open Access                                                                 Original Research Article                                            \n \n \nFigure 3:  endoscopic ultrasound image showing an endometriosis nodule (Green arrow)  \n \nFigure 4:  endoscopic ultrasound image showing normal rectal wall (Yellow arrow)  \n \n \nACKNOWLEDGEMENTS \n \nThe authors have no acknowledgements to declare and report no conflicts of interest. \n \n \nREFERENCES \n \n[1] Pishvaian AC, Ahlawat SK, Garvin D, Haddad NG. Role of EUS and EUS-guided FNA in \nthe diagnosis of symptomatic rectosigmoid endometriosis. Gastrointest Endosc 2006;63:331-\n5. https://doi.org/10.1016/j.gie.2005.06.019. \nhttps://doi.org/10.1016/j.gie.2005.06.019 \n  \n[2] Huang X, Han C, Lin K, Zhang J, Xu H, Zhang X. [Meta-analysis of ultrasonography in \ndiagnosis of deeply infiltrating endometriosis]. Zhonghua Fu Chan Ke Za Zhi 2010;45:269-72. \n \n  \n[3] Shi B, Sun B, Zhao Q, Zhang X. EUS diagnosis of rectal endometriosis. VideoGIE \n2021;6:105-7. https://doi.org/10.1016/j.vgie.2020.10.014. \nhttps://doi.org/10.1016/j.vgie.2020.10.014 \n \n  \n[4] Lim JY, Yang W-L, Huang W-F. An unusual endoscopic appearance of rectosigmoid \nendometriosis. Gastrointest Endosc 2024;99:656-7. https://doi.org/10.1016/j.gie.2023.10.015. \nhttps://doi.org/10.1016/j.gie.2023.10.015","source_license":"CC0","license_restricted":false}