{"paper_id":"15038718-bcd6-4888-adfc-285913debc25","body_text":"Abstract\nInguinal endometriosis is a less common form of endometriosis. Therefore, there is no consensus regarding its pathogenesis or treatment. In this study, we retrospectively reviewed the pathogenesis and treatment of six cases of inguinal endometriosis in our facility between 2009 and 2019. The pathogenesis of inguinal endometriosis is believed to involve hematogenous and lymphogenous extensions, as well as direct infiltration from the canal of Nuck or inguinal hernia. However, in our cases, the endometriotic lesions might have spread intravascularly from the uterine cavity. The lesions in our all cases were found as nodular or pointed hyperintensities on T1-weighted magnetic resonance imaging. In addition, all the patients experienced swelling and pain in the inguinal region during menstruation. Complete resection is often performed; however, hormonal therapy is administered to patients who do not undergo surgery, or to avoid recurrence. In our cases, dienogest was effective in reducing inguinal endometriotic lesions, improving pain, and preventing recurrence.\nSimilar content being viewed by others\nData Availability\nData is available from the authors upon reasonable request.\nCode Availability\nNot applicable.\nReferences\nGiudice LC, Kao LC. Endometriosis. Lancet. 2004;364(9447):1789–99.\nLee HJ, Park YM, Jee BC, et al. Various anatomic locations of surgically proven endometriosis: A single-center experience. Obstet Gynecol Sci. 2015;58(1):53–8.\nBlanco RG, Parithivel VS, Shah AK, et al. Abdominal wall endometriomas. Am J Surg. 2003;185(6):596–8.\nCandiani GB, Vercellini P, Fedele L, et al. Inguinal endometriosis: pathogenetic and clinical implications. Obstet Gynecol. 1991;78(2):191–4.\nSampson JA. Endometrial carcinoma of the ovary arising in endometrial tissue in that organ. Am J Obstet Gynecol. 1925;9(1):111–4.\nScott RB. Malignant changes in endometriosis. Obstet Gynecol. 1953;2(3):283–9.\nCullen T. Adenomyoma of the round ligament. Johns Hopkins Hosp Bull. 1896;7:112–4.\nDalkalitsis A, Salta S, Tsakiridis I, et al. Inguinal endometriosis: A systematic review. Taiwan J Obstet Gynecol. 2022;61(1):24–33.\nAlbutt K, Glass C, Odom S, et al. Endometriosis within a left-sided inguinal hernia sac. J Surg Case Rep. 2014;2014(5):rju046.\nArakawa T, Hirata T, Koga K, et al. Clinical aspects and management of inguinal endometriosis: A case series of 20 patients. J Obstet Gynaecol Res. 2019;45(10):2029–36.\nKobayashi H, Sumimoto K, Moniwa N, et al. Risk of developing ovarian cancer among women with ovarian endometrioma: a cohort study in Shizuoka. Japan Int J Gynecol Cancer. 2007;17(1):37–43.\nKawaguchi R, Tsuji Y, Haruta S, et al. Clinicopathologic features of ovarian cancer in patients with ovarian endometrioma. J Obstet Gynaecol Res. 2008;34(5):872–7.\nIjichi S, Mori T, Suganuma I, et al. Clear cell carcinoma arising from cesarean section scar endometriosis: case report and review of the literature. Case Rep Obstet Gynecol. 2014;2014:642483.\nOkimura H, Tatsumi H, Ito F, et al. Endometrioid carcinoma arising from diaphragmatic endometriosis treated with laparoscopy: A case report. J Obstet Gynaecol Res. 2018;44(5):972–7.\nBenoit L, Arnould L, Cheynel N, et al. Malignant extraovarian endometriosis: a review. Eur J Surg Oncol. 2006;32(1):6–11.\nBergamini A, Almirante G, Taccagni G, et al. Endometriosis-associated tumor at the inguinal site: report of a case diagnosed during pregnancy and literature review. J Obstet Gynaecol Res. 2014;40(4):1132–6.\nKondo E, Maki S, Nii M, et al. Long-term survival of a patient with malignant transformation of extragonadal endometriosis treated solely with chemotherapy: A case report. J Obstet Gynaecol Res. 2018;44(12):2186–9.\nAcknowledgements\nWe thank all the study participants and Kyoto prefectural University of Medicine clinicians for their assistance.\nFunding\nNo funding was involved with this study.\nAuthor information\nAuthors and Affiliations\nContributions\nST: Writing – original draft. HK: Writing – review & editing, Writing – original draft, Conceptualization, Supervision. FI: Investigation, Writing – original draft. KS: Investigation, Writing—original draft. TM: Writing – review & editing, Supervision.\nCorresponding author\nEthics declarations\nEthics Approval\nThis study was approved by the Institutional Review Board of Kyoto Prefectural University of Medicine on July 12, 2024. Approval number: ERB-C-3205.\nConsent to Participate\nAll participants gave informed consent.\nConsent for Publication\nConsent was given by all the authors.\nConflict of Interest\nOn behalf of all authors, the corresponding author states that there is no conflict of interest.\nAdditional information\nPublisher's Note\nSpringer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.\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\nTakatsuka, S., Kataoka, H., Ito, F. et al. Pathogenesis, Diagnosis, and Management of Inguinal Endometriosis: A Case Series of Six Patients. Reprod. Sci. 32, 647–654 (2025). https://doi.org/10.1007/s43032-025-01796-9\nReceived:\nAccepted:\nPublished:\nVersion of record:\nIssue date:\nDOI: https://doi.org/10.1007/s43032-025-01796-9","source_license":"CC0","license_restricted":false}