{"paper_id":"a1a0a16d-46f2-44d9-bbff-921c224f1102","body_text":"Endometriosis is an estrogen-dependent, inflam-\nmatory, and a benign disease that affects about 10% of \nwomen at reproductive age.\n1 Pelvic endometriosis le-\nsions are classified as peritoneal, ovarian, and infiltra-\ntive.\n2  \nDeep infiltrative endometriosis is characterized \nby invading the peritoneal tissue deeper than 5 mm.3 \nIt is usually located in areas such as the rectovaginal \nseptum, rectum, rectosigmoid colon, bladder, ureter, \nuterine ligaments, and vagina.\n4 Intestinal involvement \nof those diagnosed with infiltrative endometriosis is \napproximately 8-12%, and 90% of these cases are lo-\ncated in the colorectal segments that are thought to \ncause complete intestinal obstruction in 1%. While \n95% of the intestinal wall involvement occurs in the \nserosa and muscularis propria; the submucosa is af-\nfected in 38%, and the mucosa in 6%.\n4 In the choice of \ntreatment, it is very important to consider the patient’s \npredominant symptoms and preferences, side effect \nprofile, age, the extent of the disease, location, previous \ntreatment, and costs.\n5 Symptoms recur within 5 years in \n50% of the cases, regardless of the treatment approach.6  \nIn our study, we aim to present a case of intestinal \nendometriosis which leads to mechanical bowel ob-\nstruction by affecting the whole layer of the rectal \nwalls. \nJCOG. 2022;32(1):27-31\n27\nA Rare Cause of Bowel Obstruction Mimicking Colon Cancer: \nEndometriosis \n    Sami AÇARa,     Erman ÇİFTÇİb,     Handan ÇETİNERc,     Murat APİd \naDepartment of General Surgery, University of Health Sciences Zeynep Kamil Maternity and Children Training and Research Hospital,  \nİstanbul, Türkiye \nbDepartment of Obstetrics and Gynecology, University of Health Sciences Zeynep Kamil Maternity and Children Training and Research Hospital, \nİstanbul, Türkiye \ncDepartment of Pathology, University of Health Sciences Zeynep Kamil Maternity and Children Training and Research Hospital,  \nİstanbul, Türkiye \ndDepartment of Obstetrics and Gynecology Oncology, University of Health Sciences Zeynep Kamil Maternity and Children  \nTraining and Research Hospital, İstanbul, Türkiye\nABS TRACT Intestinal involvement is observed in a significant portion of patients diagnosed with endometriosis. Involvement is often on \nthe serosal surface of the sigmoid colon. Rarely, it takes place in the colonic mucosa and lymph nodes, causing lumen obstructi on. Colono-\nscopic biopsies may be insufficient in the differential diagnosis of malignancy and diverticulitis. We report a case of a 41-ye ar-old pre-\nmenopausal female patient with endometriosis located in the ampulla recti causing complete intestinal obstruction. Although hav ing a \nsignificant rectal mucosal mass, the diagnosis could not be made with tissue samples taken by endoscopy. During the examination , the pa-\ntient developed ileus. With the preliminary diagnosis of rectal cancer, surgical intervention was applied with oncological prin ciples, and its \ntreatment was performed with opening a diverting ileostomy. Diagnosis of rectosigmoid endometriosis is difficult. In women of c hildbearing \nage, rectosigmoid endometriosis should be kept in mind in lower gastrointestinal tract obstructions. \n \nKeywords: Endometriosis; pelvic pain; ileus; rectal neoplasms; colectomy\nDOI: 10.5336/jcog.2021-85436\nCorrespondence: Sami AÇAR \nDepartment of General Surgery, University of Health Sciences Zeynep Kamil Maternity and Children Training and Research Hospital, \nİstanbul, Türkiye \nE-mail:  acarrsami@yahoo.com  \nPeer review under responsibility of Journal of Clinical Obstetrics & Gynecology.  \nRe ce i ved: 09 Jul 2021          Received in revised form: 14 Nov 2021         Ac cep ted: 01 Feb 2022          Available online: 08 Feb 2022  \n2619-9467 / Copyright © 2022 by Türkiye Klinikleri. This is an open \naccess article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).\nTurkiye Klinikleri Journal of Internal Medicine \nJournal of Clinical Obstetrics & Gynecology\nCASE REPORT\n\n28\n CASE REPORT \nA 41-year-old gravida 0 patient presented with  \npain in the form of pressure in the pelvic area and \ndifficulty in stooling. Three different colonoscopic \nexaminations were performed at 3 different gas-\ntroenterology departments. In all these colonoscopic \nexaminations, a mass lesion starting approximately 5 \ncm from the anal entrance was seen, and it extended \nalong the rectal segment about 3-4 cm. According to \nthe Paris classification, it was graded as Is+IIb. Due \nto the presence of a Kudo pit pattern V appearance in \none area, it was not suitable for endoscopic resection \n(\nFigure 1). All pathological evaluations were com-\npatible with the granulation tissue. In the pelvic area, \na mass lesion 5x6 cm in diameter, with lobulated con-\ntoured internal small air loculations, located on the \nexpanded floor of the Douglas pouch was observed. \nDiffuse thickening up to 15 mm in a circular fashion \nat the rectal wall and the presence of many lymph \nnodes reaching 12 mm in diameter in the mesorectal \nplane were suspicious for cancer (\nFigure 2). A surgi-\ncal treatment decision was made with oncological \nprinciples for a mass lesion located in the middle rec-\ntum with occlusive nature. Due to previous abdomi-\nnal surgery, coloanal anastamosis following \nlaparotomic mesocolic and mesorectal rectosig-\nmoidal resection, and loop ileostomy was performed \n(\nFigure 3). In the definitive pathological evaluation, it \nwas reported that the resection performed was close to \ncomplete, and reactive changes was determined in 18 \nlymph nodes which were surgically removed, and a \nmass lesion with a diameter of 5.5x5x4.5 cm was re-\nported as endometriosis (\nFigure 4). Ectopic polypoid \nendometrial tissue in the rectum was located in the en-\ntire muscular, submucosal and mucosal layers, and a \nlarge polypoid mass could be seen protruding to the lu-\nmina and subsequently occluding it. The exulcerated \nsurface of the polyp with wide granulation tissue was \nshown microscopically (\nFigure 5). \nSami AÇAR et al. JCOG. 2022;32(1):27-31\n28\nFIGURE 1: Rectosigmoidoscopic view, a mass lesion with the features of being firm and smooth surfaced, including hyperemic areas that alm ost completely obstructing \nthe rectal wall. \nFIGURE 2: (A) Transverse and (B) sagittal plane of the pelvic magnetic resonance images, respectively. A mass lesion 5x6 cm in diameter with lobulated counter internal \nsmall air loculations on the expanded floor of the Douglas pouch.\n\n292929\nImmunohistochemistry technique for CD10, PAX8, es-\ntrogen alpha (ERα) and progesterone (PR) receptor, \nwas performed to confirm the presence of endometrial \nstroma and glandular tissue (\nFigure 6).  \nAn informed consent was obtained from the pa-\ntient for this case report. \n DISCUSSION \nThe presence of intestinal endometriosis can be de-\ntected as a result of examinations performed for \npelvic pain, presence of an unknown mass, and rec-\ntal bleeding. Mechanical bowel obstruction develops \ndue to areas of endometriosis extending into the \nlumen in the rectosigmoid region and sigmoid colon.\n7 \nSimilarly, endometriosis foci can cause plication and \nangulation of the intestinal segment around it.\n8 Intes-\ntinal obstruction with nodules extending from the \nDouglas pouch to the middle rectum is extremely \nrare. This is because the ampulla recti is large, cali-\nbrated and flexible, and also due to its anterior face \nbeing covered by the peritoneum. Ono et al. have re-\nported that the development of obstruction in the rec-\ntal wall occur because of narrowing of the lumen, \nultimately due to the location of the endometriosis. \nSince the diagnosis of malignancy could not be con-\nfirmed, proctectomy was performed.\n9 Lenz et al. also \npresented a case of endometriosis causing perfora-\ntion.\n10 \nSami AÇAR et al. JCOG. 2022;32(1):27-31\n29\nFIGURE 3: (A) Complete mesocolic and mesorectal excision specimen, (B) intra-abdominal view after resection.\nFIGURE 4: (A) The image shows, a mass completely obstructing the rectal lumen, (B) the view of the mass lesion right after surgically openning of the posterior rectal wall. \nThe mass is located on the ventral side of the rectum.\nFIGURE 5: Endometriosis; replacing mucosa, submucosa and muscularis propria \nand protruding lumina of the rectum as a bulky mass (H&E, x20).\n\nRectum-located endometriosis and rectal cancer \ncannot be differentiated frequently and therefore wide \nresections are performed.\n11 The incidence of malig-\nnancy associated with endometriosis is 1%, and this \nprobability is higher in foci with extraovarian loca-\ntion. Surgical treatment methods are erasion from in-\ntestinal surface, discoid excision, and segmental \nbowel resection. The method of choice depends on \nthe location of intestinal involvement, the number of \nfoci on the intestinal surface, the depth of the infil-\ntration, and whether there is a stenosis in the gut \nlumen.\n7 Avoiding segmental bowel resection, espe-\ncially in the presence of lesions close to the anal \nverge level, is important in terms of preventing pos-\nsible complications. Even in bowel resection, the \npresence of microscopic endometriosis foci at the \nlevel of 15% at the resection limits requires a careful \nevaluation at the decision-making stage. Roman et al. \nhave reported that the long-term results of radical sur-\ngery are not prognostically brighter than conservative \ntreatment, and the complication rates seem to be \nhigher.\n12 Vlek et al. have defined the transanal mini-\nmally invasive surgical technique for rectal en-\ndometriosis with deep localization.\n13   \nKazama et al. have stated that the rectal en-\ndometriosis area was prone to bleeding on endo-\nscopic examination. They have defined the presence \nof pits with flat microvessels in magnified narrow \nband imaging, and avascular areas at the tip of the \npapillary protrusions.\n14 As eutopic endometrium, ec-\ntopic glands express ER, PR, PAX-8 and stroma ex-\npress CD10. On the other hand, colonic glands are \nwell known to express CDX2 which was regarded a \nhighly sensitive marker of intestinal epithelium \nwhereas PAX-8 was reactive for organs derived from \nmullerian duct. In our case, although H+E stained \nslides were pretty clear about endometriotic nature of \nthe polypoid mass with stroma and glands, we con-\nfirmed the diagnosis with the panel of above-men-\ntioned immunohistochemical stains and CDX2 was \nnegative whereas others were all positive. \nZondervan et al. have summarized the most im-\nportant reasons for the delay in diagnosis of en-\ndometriosis. These are the absence of specific \ncomplaints and biological markers, insufficient aware-\nness and occasional normalization of the findings.\n15 \nThe uncertainty in diagnosis cannot clarify which sur-\ngical intervention should be at the decision-making \nstage. Because, in the presence of possible rectal can-\ncer, mesorectal excision and neoadjuvant treatment \nplan comes to the fore. Failure to diagnose prevents \nfurther examination. Insufficient surgical treatment in \nthe presence of cancer has a negative effect on possi-\nble local recurrence and survival. On the other hand, \nwide resection in the presence of a benign condition \nincreases the complication rate. In case of stoma open-\ning, quality of life deteriorates, and secondary surgi-\ncal interventions are required for closure.  \nSami AÇAR et al. JCOG. 2022;32(1):27-31\n30\nFIGURE 6: Positive (A) CD10, (B) PAX9, (C) ER, (D) PR immunohistochemical staining of endometriosis in rectum (IHC,x20).\n\nDespite the colonoscopic biopsies that were per-\nformed in different gastroenterology departments for \n3 times; the endometriosis could not have been diag-\nnosed and the patient underwent a surgical interven-\ntion. It should be kept in mind that endometriosis may \nbe the cause of ileus in women of childbearing age \nand should be considered in the differential diagnosis \nof both malignancy and diverticulosis coli.  \nSource of Finance \nDuring this study, no financial or spiritual support was received \nneither from any pharmaceutical company that has a direct con-\nnection with the research subject, nor from a company that pro-\nvides or produces medical instruments and materials which may \nnegatively affect the evaluation process of this study. \nConflict of Interest \nNo conflicts of interest between the authors and / or family mem-\nbers of the scientific and medical committee members or mem-\nbers of the potential conflicts of interest, counseling, expertise, \nworking conditions, share holding and similar situations in any \nfirm. \nAuthorship Contributions \nIdea/Concept: Sami Açar; Design: Sami Açar; Control/Supervi-\nsion: Murat Api, Handan Çetiner; Data Collection and/or Pro-\ncessing: Sami Açar, Handan Çetiner, Erman Çiftçi; Analysis \nand/or Interpretation: Sami Açar, Murat Api; Literature Review:  \nSami Açar, Erman Çiftçi; Writing the Article: Sami Açar; Criti-\ncal Review: Murat Api; References and Fundings: Sami Açar; \nMaterials: Sami Açar. \nSami AÇAR et al. 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