{"paper_id":"b73d8767-9190-4360-98a9-30636388f8b5","body_text":"UCLA\nUCLA Radiological Sciences Proceedings\nTitle\nAcute Large Bowel Obstruction due to Pelvic Endometriosis: A Case Report\nPermalink\nhttps://escholarship.org/uc/item/0cw9g3pp\nJournal\nUCLA Radiological Sciences Proceedings, 1(4)\nAuthors\nCain, Natalie Ann\nPatel, Maitraya\nPublication Date\n2021\nDOI\n10.5070/RS41446711\nCopyright Information\nCopyright 2021 by the author(s).This work is made available under the terms of a Creative \nCommons Attribution License, available at https://creativecommons.org/licenses/by/4.0/\n \nPeer reviewed\neScholarship.org Powered by the California Digital Library\nUniversity of California\n\nRadiological Sciences Proceedings                      \n \nAcute Large Bowel Obstruction due to Pelvic \nEndometriosis: A Case Report \n \nCain NA, MD, MPH | Patel M, MD \n \n \nAuthor Affiliation: Department of Radiological Sciences, David Geffen School of Medicine at UCLA \n \nCorresponding Author: N.C. (ncain@mednet.ucla.edu) \n \n \nUCLA Radiol Sci Proc. 2021;1(4):42-47 \n \n \nIntroduction \nEndometriosis is one of the most common benign \ngynecological conditions in women of reproductive \nage, with a prevalence of 6.6% to 16.2% among \nthis population in the United States.1 It is defined \nas the occurrence of hormone -responsive \nendometrial tissue outside of the uterine cavity. \nHowever, the pathophysiology of endometriosis is \npoorly understood. Many theories have been \nproposed to explain the ectopy of the functional \nendometrial tissue; these include retrograde \nmenstruation, Mullerian metaplasia, and \nlymphovascular dissemination.\n2 When \nendometriosis permeates deep in to the pelvis, it \ncan infiltrate the local bowel and cau se acute or \nchronic gastrointestinal symptoms. This report \npresents a rare case of acute large bowel \nobstruction (LBO) due to intestinal endometriosis \n(IE) in a woman of reproductive age. \nAbstract: Endometriosis is one of the most common benign gynecological conditions with a prevalence \nof 6.6% to 16.2% among women of reproductive age in the United States. It is defined as the occurrence \nof hormone-responsive endometrial tissue outside of the uterin e cavity. However, the pathophysiology \nof endometriosis is poorly understood. Intestinal endometriosis causing large bowel obstruction is rare \ndespite being the second most common extragenital site of endometriotic implantation. In the adult \npopulation, intestinal endometriosis is a clinical challenge because it can be mistaken for other acute \nobstructive diseases, such as colorectal carcinoma. Computed tomography lacks specificity in the \ndetection of bowel wall abnormalities that cause a large bowel obstruction, and endoscopy does not show \nan intraluminal mass. The gold standard diagnostic procedures are laparoscopy and biopsy, with \nlaparoscopy used for surgical resection of the abnormal tissue if necessary. \n \nKeywords: large bowel obstruction, endometriosis, intestinal endometriosis \nKey Points \n Intestinal endometriosis should be a part of \ndifferential diagnosis in women of \nreproductive age with a history of \nendometriosis and the symptoms of \nintestinal obstruction substantiated by \nimaging findings. \n Most frequently seen in the rectosigmoid \ncolon, intestinal endometriosis is much \nmore likely than acute abdomen  to cause \ncyclic pain , constipation, hematochezia, \ndiarrhea, tenesmus, and pain in the lower \nabdomen. \n The imaging findings for acute large bowel \nobstruction secondary to intestinal \nendometriosis might be nonspecific; \ntherefore, radiologists must consider \nendometriosis in women of reproductive \nage presenting with large bowel \nobstruction. \n\nUCLA Radiol Sci Proc. 2021;1(4):42-47                 Cain et al \n \n43 \n \nCase Presentation \nA 39- year-old woman with a medical history of \nendometriosis, laparoscopy with lysis of pelvic \nadhesions, as well as an umbilical h ernia repair \npresented to the emergency department with \nacute, spasmodic lower abdominal pain and non -\nbloody, non -bilious emesis that lasted for three \ndays. The patient reported associated abdominal \ndistention and lack of bowel movement or flatus \nsince the onset of symptoms. The patient denied \nhaving night sweats, chills, shortness of breath or \nchest pain, diarrhea, dysuria, melena, and \nhematochezia.  \nThe patient’s vital signs were as follows: \ntemperature 98.7 °F, blood pressure 168/130, \nheart rate 122, res piratory rate 18, and oxygen \nsaturation of 98% on room air. On physical \nexamination, the patient appeared to be in pain \nand distress. The patient’s abdomen was \ndistended, with hyperactive bowel sounds, \ntympanic to percussion, and diffusely tender to \npalpation with voluntary guarding. Laboratory \nvalues were noteworthy for hypokalemia, 3.3  \nmmol/L (reference range: 3.6 -5.3 mmol/L, UCLA \nclinical laboratory), likely due to losses from  \nprolonged emesis, and a high anion gap, 22 \nmmol/L (reference range: 8 -19 mmol/ L UCLA \nclinical laboratory), suggestive of lactic acidosis. \nTwo-view abdominal radiography showed marked \ndilatation of the large bowel to the level of the \nsigmoid colon and mild dilatation of the small \nbowel (Figure 1). The findings of contrast -\nenhanced co mputed tomography (CT) of the \nabdomen and the pelvis were consistent with LBO \nwith spiculated soft tissue nodularity extending \nFigure 1. Anteroposterior (AP) Abdominal Radiograph of a \n39-year-old Woman with Intestinal Endometriosis.  \nThere is marked dilatation of the large bowel to the level of the \nsigmoid colon (arrows) and mild dilatation of the small bowel \n(star), consistent with ileus. \n \nCoronal (A) and sagittal (B) abdominopelvic CT images with IV \ncontrast show findings consistent with lower bowel obstruction \n(LBO) with a spiculated soft tissue nodularity (A and B, arrows) \nextending into the wall of the sigmoid colon at the transition \npoint. \n \nB \n Sagittal view \nA \n Coronal view \nFigure 2. Contrast-enhanced Abdominopelvic CT of a 39-\nyear-old Woman with Intestinal Endometriosis. \n\nUCLA Radiol Sci Proc. 2021;1(4):42-47                 Cain et al \n \n44 \n \ninto the wall of the sigmoid colon at the transition \npoint (Figures 2, 3). \nIn preparation for sigmoidoscopy, the patient was \nprescribed to have nothing by mouth, normal \nsaline intravenously (IV), and appropriate pain \nmanagement. The following day, a \ngastroenterologist performed a sigmoidoscopy \nwith a failed attempt of intralumina l stent \nplacement. The procedure revealed normal colonic \nmucosa with extrinsic compression and \nobstruction of the sigmoid colon at 45 cm from the \nanal margin (Figure 4). There was no intraluminal \nmass. The patient was taken to the operating \nroom for a part ial exploratory laparotomy and \ntransverse loop colostomy. Histologic evaluation \nof surgical pathology of the resected sigmoid colon \nconfirmed the presence of an endometriotic \nimplant invading the colon (Figure 5 ). The \npostoperative course was complicated by infection \nof the incision site that was treated with a wet-to-\ndry dressing and 1g of cefazolin IV every eight \nhours for two days. Four months after initial \npresentation, the patient underwent colostomy \ntakedown, which entailed a partial colectomy with \nanastomosis of the proximal sigmoid colon and \nrectosigmoid junction. The postoperative course \nwas complicated by nausea and ileus that resolved \nwith symptomatic treatment. The patient was \ndischarged in a relatively good condition on \npostoperative day eight.\n \n \n \nDiscussion \nIntestinal endometriosis is defined as one of the \nforms of deeply infiltrating endometriosis with the \nlesion invading at least the subserosal and the \nmuscular layers of the bowel wall.\n2 The bowel is \nthe most common (3 -12%) extragenital site of \nendometriosis3 with a predominant occurrence in \nthe rectosigmoid junction (50 -90%), followed by \nthe small bowel (2-16%), the appendix (3-18%), \nand the cecum (2-5%). \nPatients with IE may complain of cyclic pain as well \nas cyclic constipation, hematochezia, catamenial \ndiarrhea, tenesmus, and pain in the lower \nabdomen.4 \nOnly 0.1–0.7% of cases of intestinal endometriosis \nare complicated by intestinal obstruction. 5 In the \nadult population, IE is a clinical challenge because \nit can be mistaken for other acute obstructive \ndiseases, such as colorectal carcinoma.\n2 However, \nunlike in cases of colorectal carcinoma, \nintraluminal pathology in IE is typically not \ndetected by means of a biopsy because IE rarely \nimplants at the mucosal layer of the bowel.\n3 \nFindings of CT of the abdomen and the pelvis, \nalthough useful in the diagnosis of LBO, are non -\nspecific for endometriosis-related abnormalities of \nFigure 3. 3-D CT Enterography of a 39-year-old Woman with \nIntestinal Endometriosis.  \n3-D reformatted CT e nterogram (A) reveals in fine detail the \nendometriotic implant (A, arrow) extending into the wall of the \nsigmoid colon at the transition point. 3 -D CT image \nreconstruction (B) of the portion of the sigmoid colon shows the \nendometriotic nodule (B, blue, yellow arrow) implanted into the \nwall of the sigmoid colon at the transition point with upstream \nlarge bowel obstruction (yellow). \n \nA \n 3-D reformatted CT \nenterogram \nB \n 3-D CT image \nreconstruction  \nSigmoidoscopic View (A and B)  reveals normal mucosa with \nextrinsic compression and obstruction (A, red arrow) of the \nsigmoid colon with a bluish impression (B, blue arrow) bulging \ninto the lumen against the colon wall distal to the obstruction. \nFigure 4. Endoscopic View of the Sigmoid Colon Obstruction \nin a 39-year-old Woman with Intestinal Endometriosis. \nA \n Extrinsic compression \nand obstruction \nB \n Protrusion into the \nlumen \n\n\nUCLA Radiol Sci Proc. 2021;1(4):42-47                 Cain et al \n \n45 \n \nthe bowel wall. 3 Multislice CT with colon water \ndistension has been found to be an accurate, yet \npotentially risky, imaging modality  in identifying \nlocation and extent of IE, for it exposes women of \nreproductive age to ionizing radiation and \niodinated contrasts. 6 Although having similar \nlimitations associated with ionizing radiation and \nprocedural discomfort, CT -based virtual \ncolonography (CTC) is another imaging modality \nfor diagnosing IE as it relates to morphologic \nalterations of the bowel lumen.\n7 With its excellent \nmultiplanar capabilities and contrast resolution, \nmagnetic resonance (MR) is yet another tool  that \nprovides high sensitivity (88%), specificity (98%), \nand diagnostic accuracy (96%), in imaging of \npatients with IE.\n4,8 When suspicion for IE is high, \ntransvaginal ultrasound, in the hands of an \nexperienced sonographer, can aid in visualizing \nendometriosis of the rectosigmoid colon. 4,8 The \ngold standard diagnostic procedures are \nlaparoscopy and biopsy, with laparoscopy used for \nsurgical resection of the abnormal tissue if \nnecessary.3,9 \nIn our patient, the diagnosis of endometriosis of \nthe intestine was first suspected on CT imaging; it \nwas guided by a high clinical suspicion based on \nthe patient’s history of endometriosis. Endoscopic \nfindings reinforced our suspicion, and histologic  \nexamination of surgical pathology confirmed the \ndiagnosis of rectosigmoid endometriosis. \nThe literature suggests that, compared with \nnonemergency interventions, emergency \ninterventions for acute endometriotic LBO often \nresult in prolonged hospital stay and increased \ncomplications and mortality.\n10 Operation may be \neven more dif ficult in case of extensive pelvic \nendometriosis; because of distorted pelvic \nanatomy, it may require a multidisciplinary team \nwith skilled gynecologic and colorectal surgeons. \nThese operations often result in major \ncomplications. One such complication, \nrectovaginal fistula, likely related to anastomotic \nleakage, was described in the paper\n7 reporting the \noutcomes of colorectal resection in a cohort of six \npatients. However, long -term follow -up of these \npatients showed no recurrences of IE.7 Endoscopic \ndecompression by self -expandable metallic \ncolorectal stents (SEMS) as a bridge to nonurgent \nsurgery allows the multidisciplinary team to \noptimize patient preparation for an elective \nprocedure.10 Only a few cases of treatment of \nacute endometriotic LBO were desc ribed in the \nliterature.10 However, as suggested by Forshaw et \nal,11 although the use of SEMS in the treatment of \ndiverticular disease, anastomotic stricture, and \nrectal endometriosis might benefit some patients \nFigure 5. Microscopic Examination of the Resected Specimen \nin a Case of Intestinal Endometriosis in a 39-year-old Woman. \nPhotomicrographs A and B; Low power view of the surgically \nresected large bowel (A) shows endometrial glands and stroma \nwithin the muscularis propria of the sigmoid colon (A, red \narrow). Immunohistochemical staining (B) shows estrogen \nreceptor positivity seen as the strong bronze staining of the \ncells (B, blue arrow). These findings confirm the diagnosis of \nendometriosis infiltrating the sigmoid colon. \nB \n Immunohistochemical staining \nA \n Hematoxylin-eosin staining \n\n\nUCLA Radiol Sci Proc. 2021;1(4):42-47                 Cain et al \n \n46 \n \nwith benign colorectal disease,  it is controversial \nand should be approached carefully as it has a high \nrate of complications, including stent migration \nand failure.  \nIn conclusion, acute LBO is a rare complication of \nIE and requires urgent surgical resection. IE \nshould be a part of differential diagnosis in women \nof reproductive age with a history of endometriosis \nand symptoms of intestinal obstruction \nsubstantiated by imaging findings. \n \n \nAcknowledgements \nWe thank Hanlin Wang, MD, PhD in the Department of \nPathology, David Geffen School of Medicine at UCLA , for \ncontributing the images of histopathologic evaluation. We \nthank Kalyani Vyapari, MSc in the Q3D Imaging Lab, \nDepartment of Radiological Sciences, David Geffen School of \nMedicine at UCLA, for contributing 3-D rendered images. \n \n \nAuthor Contributions \nConceptualization, M.P. and N.A.C.; Acquisition, analysis, \ninterpretation of data, and writing – original draft preparation, \nN.A.C.; Review and editing, M.P. and N.A.C.; Supervision, M.P. \nAll authors agree to be accountable for all aspects of the work \nin ensuring that questions related to the accuracy or integrity \nof any part of the work are appropriately investigated and \nresolved. All authors had full access to all the data in the study \nand take responsibility for the integrity of the data and the \naccuracy of the data analysis. \n \n \nDisclosures \nNone to report. \n \nReferences \n1. Fuldeore MJ, Soliman AM. Prevalence and symptomatic \nburden of diagnosed endometriosis in the United States: \nnational estimates from a cross-sectional survey of 59,411 \nwomen. Gynecol Obstet Invest . 2017;82(5):453- 461. \nDOI: 10.1159/000452660\n \n2. Sarofim M, Attwell -Heap A, Trautman J, Kwok A, Still A. \nUnusual case of acute large bowel obstruction: \nendometriosis mimicking sigmoid malignancy. ANZ J Surg. \n2019;89(11):E542-E543. DOI: 10.1111/ans.14869\n \n3. Alexandrino G, Lourenço LC, Carvalho R, Sobrinho C, Horta \nDV, Reis J. Endometriosis: A rare cause of large bowel \nobstruction. GE Port J Gastroenterol.  2018;25(2):86–90. \nDOI: 10.1159/000480707\n \n4. Habib N, Centini G, Lazzeri L, et al. Bowel endometriosis: \nCurrent perspectives on diagnosis and treatment. Int J of \nWomen’s Health. 2020;12:35-47. Published 2020 Jan 29. \nDOI: 10.2147/IJWH.S190326\n \n5. Allan Z. A case of endometriosis causing acute large bowel \nobstruction. Int J Surg Case Rep . 2018;42:247- 249. \nDOI: 10.1016/j.ijscr.2017.12.031\n \n6. Iosca S, Lumia D, Bracchi  E, et al. Multislice computed \ntomography with colon water distension (MSCT -c) in the \nstudy of intestinal and ureteral endometriosis. Clin \nImaging. 2013;37(6):1061- 1068. \nDOI: 10.1016/j.clinimag.2013.07.003 \n7. Ruffo G, Crippa S, Sartori A, Partelli S, Minelli L, Falconi M. \nManagement of rectosigmoid obstruction due to severe \nbowel endometriosis. Updates Surg . 2014;66(1):59- 64. \nDOI: 10.1007/s13304-013-0240-1\n \n8. Turocy JM, Benacerraf BR. Transvaginal sonography in the \ndiagnosis of deep infiltrating endometriosis: A review. J \nClin Ultrasound . 2017;45(6):313- 318. \nDOI: 10.1002/jcu.22483 \n9. Pramateftakis MG, Psmoas S, Kanellos D, et al. Large \nbowel obstruction due to endometriosis. Tech Coloproctol. \n2010;14 Suppl 1:S87 -S89.  DOI: 10.1007/s10151-010-\n0616-x \n10. Whelton C, Bhowmick  A. Acute Endometrial Bowel \nObstruction – A Rare Indication for Colonic Stenting. Int J \nSurg Case Rep . 2013;4(2):160- 163. \nDOI: 10.1016/j.ijscr.2012.11.007  \n11. Foreshaw MJ, Sankararajah D, Stewart M, Parker MC. Self-\nexpanding metallic stents in the treatment of benign \ncolorectal disease: indications and outcomes. Colorectal \nDis. 2006;8(2):102-111. DOI:  \n10.1111/j.1463-\n1318.2005.00806.x","source_license":"CC0","license_restricted":false}