{"paper_id":"a28ee47c-fcf9-4dd2-b3bb-11ad805d6249","body_text":"Received\n 07/22/2019 \nReview began\n 07/26/2019 \nReview ended\n 09/13/2019 \nPublished\n 10/01/2019\n© Copyright \n2019\nAdeboye et al. This is an open access\narticle distributed under the terms of the\nCreative Commons Attribution License\nCC-BY 3.0., which permits unrestricted\nuse, distribution, and reproduction in any\nmedium, provided the original author and\nsource are credited.\nEndometriosis of the Vermiform Appendix\nPresenting as Acute Appendicitis\nAdeolu Adeboye \n \n, \nGabriel O. Ologun \n \n, \nDaniel Njoku \n \n, \nJean Miner \n1.\n General Surgery, Guthrie Clinic/Robert Packer Hospital, Sayre, USA \n2.\n General Surgery, Robert Packer\nHospital/Guthrie Clinic, Sayre, USA \n3.\n Biological Science, Howard University, Washington, DC, USA \n4.\n General Surgery,\nRobert Packer Hospital/ Guthrie Clinic, Sayre, USA\nCorresponding author: \nGabriel O. Ologun, \ngabe.ologun@gmail.com\nAbstract\nEndometriosis is characterized by the growth of endometrial tissue outside the uterine cavity. Endometriosis\nof the appendix is rare and its preoperative diagnosis is difficult. We report the case of a postmenopausal\nwoman who presented with right lower quadrant abdominal pain concerning for acute appendicitis.\nHistopathological examination of her appendix revealed endometriosis and her abdominal pain resolved\nafter appendectomy.\nCategories:\n Emergency Medicine, Obstetrics/Gynecology, General Surgery\nKeywords:\n appendix, appendicitis, endometriosis, abdominal pain, appendectomy\nIntroduction\nEndometriosis is the presence of functioning ectopic endometrial tissues outside the lining of the uterine\ncavity. It is usually asymptomatic; when symptoms are present, they are often based on the location of the\nimplants \n[1]\n. Endometriosis of the appendix is rare. Patients may present with a wide range of symptoms,\nincluding acute appendicitis, intestinal perforation, intestinal obstruction or lower gastrointestinal bleeding\n[1-3]\n. Right lower quadrant abdominal pain has been described as one of the most common symptoms of\nappendiceal endometriosis \n[1]\n. Preoperative diagnosis is difficult, as imaging findings are usually\nindistinguishable from acute appendicitis. The definitive diagnosis is usually established by\nhistopathological examination of the appendix. We report a case of endometriosis of the appendix\npresenting as right lower quadrant abdominal pain in a 50-year-old woman. To our knowledge, there have\nbeen no previous reports of isolated appendiceal endometriosis in a postmenopausal female without pelvic\nspread as found in this case.\nCase Presentation\nA 50-year-old postmenopausal female who presented to the emergency department with a three-\nweek history of sharp, non-radiating, intermittent, moderate right lower quadrant abdominal pain. Her\nhistory is significant for hypertension, adenomyosis with abnormal uterine bleed for which she underwent\ntotal abdominal hysterectomy with bilateral salpingectomy. She is a non-smoker.\nOn examination, she was afebrile and hemodynamically normal. Laboratory evaluation revealed white blood\ncell count 11.6 K/uL, hemoglobin 12.1 g/dL, platelet count 262 K/uL. Computed tomography (CT) scan of the\nabdomen and pelvis with contrast showed a very thickened, irregular appendix with trace adjacent fluid that\nwas concerning for appendicitis; the thickness of the appendix also raised some concern for potential\nunderlying appendiceal neoplasm (Figure \n1\n). The patient underwent colonoscopic evaluation, which was\nunremarkable. Surgery was then performed under general anesthesia. Intraoperatively, a 1.5-cm nodule was\nnoted with the tip of the appendix (Figure \n2\n), there was no evidence of pelvic endometriosis. An\nappendectomy was performed and the specimen was sent off for pathology evaluation.\n1\n2\n3\n4\n \n Open Access Case\nReport\n \nDOI:\n 10.7759/cureus.5816\nHow to cite this article\nAdeboye A, Ologun G O, Njoku D, et al. (October 01, 2019) Endometriosis of the Vermiform Appendix Presenting as Acute Appendicitis. Cureus\n11(10): e5816. \nDOI 10.7759/cureus.5816\n\nFIGURE\n 1: Coronal computed tomography of the abdomen and pelvis\nrevealing a thick, irregular appendix periappendiceal stranding\nconcerning for acute appendicitis (yellow oval ring).\n2019 Adeboye et al. Cureus 11(10): e5816. DOI 10.7759/cureus.5816\n2\n of \n4\n\nFIGURE\n 2: Intraoperative imaging of pelvic nodule noted in the tip of the\nappendix (black oval ring).\nHistopathology demonstrated endometriosis involving the appendix without involvement of other pelvic\norgans. The patient had an uneventful recovery and resolution of her abdominal discomfort.\nDiscussion\nEndometriosis is characterized by the growth of endometrial tissue outside the uterine cavity. It is well\nknown as a cause of pelvic pain and infertility, affecting approximately 70% of women with chronic pelvic\npain, and up to 50% of women with infertility. However, it can also cause acute pelvic or abdominal pain\nthat is severe enough to prompt the patient to seek emergency medical care \n[1]\n. The majority of endometrial\nimplants occur in the dependent parts of the female pelvis. A study that assessed the anatomic distribution\nof ectopic endometrium by investigating the location of implants and adhesions in 182 patients found that\nthe most common sites of implants are the ovaries (54.9%). This was followed by the posterior broad\nligament (35.2%), anterior cul-de-sac (34.6%), the posterior cul-de-sac (34.0%), and the uterosacral ligament\n(28.0%). Another study that looked at 1573 consecutive patients with endometriosis reports involvement of\nthe GI tract in 5.4% of the patients. Other studies have shown that when endometriosis involves the GI tract,\nit commonly involves the recto-sigmoid (72.4%), the recto-vaginal septum (13.5%), small intestine (7.0%),\ncecum (3.6%) and the appendix (3%) \n[1]\n. Endometriosis of the GI tract is therefore uncommon, and when it\noccurs, it rarely involves the appendix. Involvement of the appendix may present as appendicitis or\nappendicular mass that may mimic a neoplasm \n[1]\n.\nThe prevalence of appendiceal endometriosis is about 0.4 to 1% in the general population and about 4\nto 22% among patients with endometriosis \n[4]\n. Endometriosis is a risk factor for developing appendiceal\nendometriosis; patients with deep infiltrating endometriosis have a six-fold higher risk of developing\nappendiceal endometriosis compared with women without endometriosis \n[4]\n.\nClinically patients may present with acute appendicitis, or manifest atypical symptoms such as abdominal\ncolic, nausea, and melena and in some situations, inverted or bulbous appendiceal orifice on colonoscopy, or\nsometimes the patient may be asymptomatic \n[5,6]\n. Laboratory and imaging studies are usually non-specific\nin the diagnosis of appendiceal endometriosis. The diagnosis can be made by histopathology, when\nendometrial glands and stroma are present outside of the uterus. It usually involves the serosa and subserosa\nin the intestine \n[5,6]\n. CT scan may demonstrate evidence of acute appendicitis or appendiceal abnormality\n[6]\n.\nThe treatment of appendiceal endometriosis is primarily surgical. Medical treatments such as hormonal\ntherapy are secondary \n[5]\n. The goal of surgical treatment is to remove the disease and restore the bowel\ncontinuity and function. This may require appendectomy, ileocecectomy or right hemicolectomy in the case\nof endometriosis of the appendix. In patients with severe endometriosis incidental appendectomy is\nrecommended because endometriosis of the appendix may be missed on visual inspection \n[6]\n.\nSeveral theories exist regarding the pathogenesis of extrauterine endometriosis including: implantation or\nretrograde menstruation theory; direct transplantation and dissemination theory; coelomic metaplasia\ntheory; the induction theory; the embryonic rest theory and the cellular immunity theory \n[5]\n. The coelomic\nmetaplasia theory that the peritoneal cavity contains progenitor cells capable of differentiating into\nendometrial tissue, the induction theory proposes that sloughed endometrium produces substances that\n2019 Adeboye et al. Cureus 11(10): e5816. DOI 10.7759/cureus.5816\n3\n of \n4\n\ncause endometriosis. On the other hand, the embryonic rest theory hypothesizes that specific stimulus to a\nMullerian origin cell nest produces endometriosis, and the cellular immunity theory suggests that\nalterations in cell-mediated and humoral immunity allow ectopic endometrial cells to proliferate \n[5]\n.\nIn our patient, her history of adenomyosis further increased her risk for appendiceal endometriosis;\nadenomyosis has been reported to have a high incidence of association with uterine abnormalities.\nEndometriosis and adenomyosis have been described as variants of the same disease process, with both\nresulting from the exaggeration of the same physiologic mechanism \n[1]\n.\nConclusions\nEndometriosis of the appendix is rare and difficult to diagnose perioperatively as these patients present with\na range of symptoms including symptoms of acute appendicitis as in our case report. High index of suspicion\nis needed for accurate diagnosis in women with a history of gynecologic disease and should be included in\nthe differential diagnosis for right lower quadrant pain. The mechanism of endometriosis is still unclear.\nAdditional Information\nDisclosures\nHuman subjects:\n Consent was obtained by all participants in this study. \nConflicts of interest:\n In\ncompliance with the ICMJE uniform disclosure form, all authors declare the following: \nPayment/services\ninfo:\n All authors have declared that no financial support was received from any organization for the\nsubmitted work. \nFinancial relationships:\n All authors have declared that they have no financial\nrelationships at present or within the previous three years with any organizations that might have an\ninterest in the submitted work. \nOther relationships:\n All authors have declared that there are no other\nrelationships or activities that could appear to have influenced the submitted work.\nReferences\n1\n. \nHwang BJ, Jafferjee N, Paniz-Mondolfi A, Baer J, Cooke K, Frager D: \nNongynecological endometriosis\npresenting as an acute abdomen\n. Emerg Radiol. 2012, 19:463-471. \n10.1007/s10140-012-1048-x\n2\n. \nUncu H, Taner D: \nAppendiceal endometriosis: two case reports\n. Arch Gynecol Obstet. 2008, 278:273-275.\n10.1007/s00404-008-0570-2\n3\n. \nMittal VK, Choudhury SP, Cortez JA: \nEndometriosis of the appendix presenting as acute appendicitis\n. Am J\nSurg. 1981, 142:519-521. \n10.1016/0002-9610(81)90389-5\n4\n. \nMoulder JK, Siedhoff MT, Melvin KL, Jarvis EG, Hobbs KA, Garrett J: \nRisk of appendiceal endometriosis\namong women with deep-infiltrating endometriosis\n. Int J Gynaecol Obstet. 2017, 139:149-154.\n10.1002/ijgo.12286\n5\n. \nYoon J, Lee YS, Chang H-S, Park CS: \nEndometriosis of the appendix\n. Ann Surg Treat Res. 2014, 87:144-147.\n10.4174/astr.2014.87.3.144\n6\n. \nSaleem A, Navarro P, Munson JL, Hall J: \nEndometriosis of the appendix: report of three cases\n. Int J Surg Case\nRep. 2011, 2:16-19. \n10.1016/j.ijscr.2010.11.001\n2019 Adeboye et al. Cureus 11(10): e5816. DOI 10.7759/cureus.5816\n4\n of \n4","source_license":"CC0","license_restricted":false}