{"paper_id":"0e2bc79c-fbaf-44da-994c-a1bc103f71b1","body_text":"Abstract\nSubepithelial lesions (SELs) in the lower gastrointestinal tract are rare, and diagnosis and treatment of colorectal SELs are often challenging. Although endoscopic ultrasound-guided tissue acquisition (EUS-TA) is useful for minimally invasive histological diagnosis, few reports have described its use for right-sided colonic SELs because advancing an oblique-viewing echoendoscope into the right colon is difficult. A 30-year-old woman was referred to our hospital after colonoscopy revealed a protruding cecal lesion suggestive of an SEL. Contrast-enhanced computed tomography showed a 37-mm contrast-enhancing mass and an adjacent lesion, thought to be an enlarged lymph node, and gastrointestinal stromal tumor was suspected. A forward-viewing echoendoscope was inserted transanally and advanced successfully to the cecum in 4 min. EUS-TA of the cecal mass was performed using a 19-gauge fine-needle biopsy needle, and EUS-TA of the adjacent lesion was performed using a 25-gauge fine-needle biopsy needle. Histopathological and immunohistochemical examinations showed endometrial glands and stroma with positivity for estrogen receptor, progesterone receptor, and CD10, leading to a definitive diagnosis of endometriosis. This diagnosis enabled initial non-surgical management without immediate surgery.\nSimilar content being viewed by others\nReferences\nLandi B, Palazzo L. The role of endosonography in submucosal tumors. Best Pract Res Clin Gastroenterol. 2009;23:679–701.\nCazacu IM, Singh BS, Luzuriaga Chavez AA, et al. EUS and EUS-guided FNA/core biopsies in the evaluation of subepithelial lesions of the lower gastrointestinal tract: 10-year experience. Endosc Ultrasound. 2020;9:329–36.\nNguyen-Tang T, Shah JN, Sanchez-Yague A, Binmoeller KF. Use of front-view forward-array echoendoscope to evaluate right colonic subepithelial lesions. Gastrointest Endosc. 2010;72:606–10.\nInoue T, Okumura F, Sano H, et al. Impact of endoscopic ultrasound-guided fine-needle biopsy on the diagnosis of subepithelial tumors: a propensity score-matching analysis. Dig Endosc. 2019;31:156–63.\nInoue A, Ota S, Yamasaki M, et al. Gastrointestinal stromal tumors: a comprehensive radiological review. Jpn J Radiol. 2022;40:1105–20.\nMiettinen M, Lasota J. Gastrointestinal stromal tumors. Gastroenterol Clin North Am. 2013;42:399–415.\nGong EJ, Kim DH. Endoscopic ultrasonography in the diagnosis of gastric subepithelial lesions. Clin Endosc. 2016;49:425–33.\nTao L, Chen Y, Fang Q, et al. Feasibility and clinical value of linear endoscopic ultrasonography imaging in the lower gastrointestinal subepithelial lesions. Sci Rep. 2024;14:6468.\nSasaki Y, Niwa Y, Hirooka Y, et al. The use of endoscopic ultrasound-guided fine-needle aspiration for investigation of submucosal and extrinsic masses of the colon and rectum. Endoscopy. 2005;37:154–60.\nIshikawa T, Yamao K, Mizutani Y, et al. A prospective study on the histological evaluation of type 1 autoimmune pancreatitis using endoscopic ultrasound-guided fine needle biopsy with a 19-gauge Franseen needle. J Hepatobiliary Pancreat Sci. 2024;31:581–90.\nZhang XC, Li QL, Yu YF, et al. Diagnostic efficacy of endoscopic ultrasound-guided needle sampling for upper gastrointestinal subepithelial lesions: a meta-analysis. Surg Endosc. 2016;30:2431–41.\nTateishi H, Tsuruta O, Nakahara K, et al. Endoscopic findings and diagnostic considerations for rectal endometriosis Japanese. Shokaki Naishikyo. 2004;16:196–200.\nAcknowledgements\nWe would like to thank all the medical staff at Tane General Hospital who were involved in this study and assisted with the endoscopic procedures.\nFunding\nNone.\nAuthor information\nAuthors and Affiliations\nContributions\nKK: Writing—original draft. KT: Supervision, Writing—review & editing. SO, KM, YK, EN, EA and SA: Investigation.\nCorresponding author\nEthics declarations\nConflict of interest\nThe authors declare that they have no conflict of interest.\nInformed consent\nInformed consent was obtained from the patient for publication of her case details and the associated images.\nAnimal or Human rights\nAll procedures followed were in accordance with the ethical standards of the institutional and national guidelines and with the Helsinki Declaration of 1975, as revised in 2024.\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\nKawasaki, K., Takeshita, K., Otachi, S. et al. Endometriosis in the cecum diagnosed via forward-viewing endoscopic ultrasound-guided tissue acquisition with a 19G fine-needle biopsy needle: a case report. Clin J Gastroenterol (2026). https://doi.org/10.1007/s12328-026-02392-3\nReceived:\nAccepted:\nPublished:\nVersion of record:\nDOI: https://doi.org/10.1007/s12328-026-02392-3","source_license":"public-domain-us","license_restricted":false}