{"paper_id":"44fd9047-c55d-4cee-ab59-6f005993a19c","body_text":"Abstract\nObjective\nTo assess the prevalence of endometriosis of the appendix and the association with other pelvic localizations of the disease and to provide pathogenesis hypotheses.\nMethods\nMonocentric, observational, retrospective, cohort study. Patients undergoing laparoscopic endometriosis surgery in our tertiary referral center were consecutively enrolled. The prevalence of the different localizations of pelvic endometriosis including appendix involvement detected during surgery was collected. Included patients were divided into two groups based on the presence of appendiceal endometriosis. Women with a history of appendectomy were excluded.\nMeasurements and main results.\nFour hundred-sixty patients were included for data analysis. The prevalence of appendiceal endometriosis was 2.8%. In patients affected by endometriosis of the appendix, concomitant ovarian and/or bladder endometriosis were more frequently encountered, with prevalence of 53.9% (vs 21.0% in non-appendiceal endometriosis group, p = 0.005) and 38.4% (vs 11.4%, p = 0.003), respectively. Isolated ovarian endometriosis was significantly associated to appendiceal disease compared to isolated uterosacral ligament (USL) endometriosis or USL and ovarian endometriosis combined (46.2% vs 15.4% vs 7.7%, p < 0.001). Poisson regression analysis revealed a 4.1-fold and 4.4-fold higher risk of ovarian and bladder endometriosis, respectively, and a 0.1-fold risk of concomitant USL endometriosis in patients with appendiceal involvement.\nConclusion\nInvolvement of the appendix is not uncommon among patients undergoing endometriosis surgery. Significant association was detected between appendiceal, ovarian, and bladder endometriosis that may be explained by disease dissemination coming from endometrioma fluid shedding. Given the prevalence of appendiceal involvement, counseling regarding the potential need for appendectomy during endometriosis surgery should be considered.\nSimilar content being viewed by others\nData availability\nThe data underlying this article cannot be shared publicly due to the need for privacy of individuals that participated in the study. The data will be shared on reasonable request to the corresponding author.\nReferences\nVercellini P, Viganò P, Somigliana E, Fedele L (2014) Endometriosis: pathogenesis and treatment. Nat Rev Endocrinol 10(5):261–275\nJohn St. BP, Snider AE, Kellermier H, Minhas S, Nottingham JM (2018) Endometriosis of the appendix presenting as acute appendicitis with unusual appearance. Int J Surg Case Rep 53:211–213\nHabib N, Centini G, Lazzeri L, Amoruso N, El Khoury L, Zupi E et al (2020) Bowel endometriosis: current perspectives on diagnosis and treatment. Int J Women’s Health 12:35–47\nCharatsi D, Koukoura O, Ntavela IG, Chintziou F, Gkorila G, Tsagkoulis M et al (2018) Gastrointestinal and urinary tract endometriosis: a review on the commonest locations of extrapelvic endometriosis. Adv Med 2018:1–11\nGimonet H, Laigle-Quérat V, Ploteau S, Veluppillai C, Leclère B, Frampas E (2016) Is pelvic MRI in women presenting with pelvic endometriosis suggestive of associated ileal, appendicular, or cecal involvement? Abdom Radiol 41(12):2404–2410\nAfors K, Centini G, Fernandes R, Murtada R, Zupi E, Akladios C et al (2016) Segmental and discoid resection are preferential to bowel shaving for medium-term symptomatic relief in patients with bowel endometriosis. J Minim Invasive Gynecol 23(7):1123–1129\nVercellini P, Sergenti G, Buggio L, Frattaruolo MP, Dridi D, Berlanda N (2021) Advances in the medical management of bowel endometriosis. Best Pract Res Clin Obstet Gynaecol 71:78–99\nGustofson RL, Kim N, Liu S, Stratton P (2006) Endometriosis and the appendix: a case series and comprehensive review of the literature. Fertil Steril 86(2):298–303\nMoulder JK, Siedhoff MT, Melvin KL, Jarvis EG, Hobbs KA, Garrett J (2017) Risk of appendiceal endometriosis among women with deep-infiltrating endometriosis. Int J Gynecol Obstet 139(2):149–154\nUwaezuoke S, Udoye E, Etebu E (2013) Endometriosis of the appendix presenting as acute appendicitis: a case report and literature review. Ethiop J Health Sci 23(1):4\nUohara JK, Kobara TY (1975) Endometriosis of the appendix. Am J Obstet Gynecol 121(3):423–426\nBerker B, LaShay N, Davarpanah R, Marziali M, Nezhat CH, Nezhat C (2005) Laparoscopic appendectomy in patients with endometriosis. J Minim Invasive Gynecol 12(3):206–209\nAlabiso G, Alio L, Arena S, Di Prun AB, Bergamini V, Berlanda N et al (2015) How to manage bowel endometriosis: the ETIC approach. J Minim Invasive Gynecol 22(4):517–529\nMabrouk M, Raimondo D, Mastronardi M, Raimondo I, Del Forno S, Arena A et al (2020) Endometriosis of the appendix: when to predict and how to manage—A multivariate analysis of 1935 endometriosis cases. J Minim Invasive Gynecol 27(1):100–106\nAfors K, Murtada R, Centini G, Fernandes R, Meza C, Castellano J et al (2014) Employing laparoscopic surgery for endometriosis. Womens Health (Lond Engl) 10(4):431–443\nElm EV, Altman DG, Egger M, Pocock SJ, Gøtzsche PC, Vandenbroucke JP (2007) Strengthening the reporting of observational studies in epidemiology (STROBE) statement: guidelines for reporting observational studies. BMJ 335(7624):806–808\nBreivik H, Borchgrevink PC, Allen SM, Rosseland LA, Romundstad L, Breivik Hals EK et al (2008) Assessment of pain. Br J Anaesth 101(1):17–24\nAllahqoli L, Mazidimoradi A, Momenimovahed Z, Günther V, Ackermann J, Salehiniya H et al (2023) Appendiceal endometriosis: a comprehensive review of the literature. Diagnostics 13(11):1827\nPadovesi Mota IL, Klajner S, da Costa Gonçalves MO, Passman LJ, Podgaec S (2015) Appendiceal nodules in the setting of endometriosis can be carcinoid tumors. JSLS. https://doi.org/10.4293/JSLS.2015.00028\nHarper AJ, Soules MR (2002) Appendectomy as a consideration in operations for endometriosis. Int J Gynecol & Obstet 79(1):53–54\nHori T, Harada H, Yamamoto M, Yamada M, Yazawa T, Sasaki B et al (2021) Ectopic endometriosis, menstruation, and acute appendicitis: a thought-provoking case. Int J Surg Case Rep 80:105605\nGuo C, Chen MZ, Chiu T, Condous G, Barto W (2023) The appendix in endometriosis. Aust NZ J Obst Gynaeco 63(6):792–796\nRaimondo D, Borghese G, Cocchi L, Raffone A, Casadio P, Mollo A et al (2023) Laparoscopic appendectomy for gynecologists in five steps. Gynecol Minim Invasive Ther 12(3):183–184\nExacoustos C, De Felice G, Pizzo A, Morosetti G, Lazzeri L, Centini G et al (2018) Isolated ovarian endometrioma: a history between myth and reality. J Minim Invasive Gynecol 25(5):884–891\nNisolle M, Donnez J (1997) Peritoneal endometriosis, ovarian endometriosis, and adenomyotic nodules of the rectovaginal septum are three different entities. Fertil Steril 68(4):585–596\nXu X, Chen Y, Yu Q, Wang J, Xu P, Zhu L et al (2022) The presence of living endometrial cells in ovarian endometriotic cyst fluid may contribute to the recurrence of endometriosis after surgical excision of endometriomas. J Ovarian Res 15(1):89\nVercellini P, Abbiati A, Vigano P, Somigliana ED, Daguati R, Meroni F et al (2007) Asymmetry in distribution of diaphragmatic endometriotic lesions: evidence in favour of the menstrual reflux theory. Human Reprod 22(9):2359–67\nCzyzyk A, Podfigurna A, Szeliga A, Meczekalski B (2017) Update on endometriosis pathogenesis. Minerva Obstet Gynecol. https://doi.org/10.23736/S0026-4784.17.04048-5\nDonnez J, Spada F, Squifflet J, Nisolle M (2000) Bladder endometriosis must be considered as bladder adenomyosis. Fertil Steril 74(6):1175–1181\nSomigliana E, Vercellini P, Gattei U, Chopin N, Chiodo I, Chapron C (2007) Bladder endometriosis: getting closer and closer to the unifying metastatic hypothesis. Fertil Steril 87(6):1287–1290\nVillaescusa M, Andres MP, Amaral AC, Barbosa RN, Abrão MS (2021) Endometriosis and its correlation with carcinoid tumor of the appendix: a systematic review. Minerva Obstet Gynecol 73(5):606–613\nFeldhaus DJ, Harris RK, Dayal SD (2020) Appendiceal endometriosis presenting as possible cecal mass. Am Surg 86(11):1528–1530. https://doi.org/10.1177/0003134820933606\nRoss WT, Chu A, Li L, Kunselman AR, Harkins GJ, Deimling TA, Benton AS (2021) Appendectomy in the surgical management of women with endometriosis and pelvic pain. Int J Gynaecol Obstet 154(3):526–531\nParra RS, Feitosa MR, Biagi GBB, Brandão DF, Moraes MMFDS, Silvestre L, Zanardi JVC, Sato Junior NH, Féres O, da Rocha JJR (2020) Neuroendocrine appendiceal tumor and endometriosis of the appendix: a case report. J Med Case Rep 14(1):152. https://doi.org/10.1186/s13256-020-02490-x\nŠkegro B, Bjedov S, Mikuš M, Mustač F, Lešin J, Matijević V, Ćorić M, Elveđi Gašparović V, Medić F, Sokol KV (2021) Endometriosis, pain and mental health. Psychiatr Danub 33(4):632–636\nFunding\nNone.\nAuthor information\nAuthors and Affiliations\nContributions\nG.C.: Conceptualization, Data curation, Investigation, Methodology, Visualization, Writing—original draft; Writing—review & editing. A.G.: Conceptualization, Data curation, Methodology, Project administration, Supervision, Validation, Writing—original draft; Writing—review & editing. I.C.: Conceptualization, Project administration, Supervision, Validation, Visualization, Writing—review & editing. A.C.: Conceptualization, Investigation, Project Administration, Supervision, Validation, Visualization, Writing—review & editing. M.C.: Conceptualization, Supervision, Validation, Visualization, Writing—review & editing. H.F.: Data curation, Investigation, Resources. F.F.: Conceptualization, Supervision, Validation, Writing—review & editing. M.P.: Data curation, Investigation, Formal Analysis, Software. F.G.M.: Conceptualization, Investigation, Project Administration, Supervision, Validation, Visualization, Writing—review & editing. E.Z.: Conceptualization, Data curation, Investigation, Methodology, Visualization, Writing—original draft; Writing—review & editing. L.L.: Conceptualization, Investigation, Methodology, Project administration, Supervision, Validation, Writing—original draft.\nCorresponding author\nEthics declarations\nConflict of interest\nThe authors have no conflicts of interest.\nAdditional information\nPublisher's Note\nSpringer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.\nSupplementary Information\nBelow is the link to the electronic supplementary material.\nRights and permissions\nSpringer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.\nAbout this article\nCite this article\nCentini, G., Ginetti, A., Colombi, I. et al. Endometriosis of the appendix: prevalence, associated lesions, and proposal of pathogenetic hypotheses. A retrospective cohort study with prospectively collected data. Arch Gynecol Obstet 310, 1669–1675 (2024). https://doi.org/10.1007/s00404-024-07650-8\nReceived:\nAccepted:\nPublished:\nVersion of record:\nIssue date:\nDOI: https://doi.org/10.1007/s00404-024-07650-8","source_license":"CC0","license_restricted":false}