Giant endometrioma of the canal of nuck mimicking a vulvar mass: a rare case and narrative review

Background Endometriosis of the canal of Nuck is an extremely rare manifestation of extrapelvic endometriosis that may mimic common groin pathologies such as inguinal hernia or hydrocele, often leading to diagnostic difficulty and delayed recognition. Case Presentation We report the case of a 29-year-old nulliparous woman who presented with a gradually enlarging painless swelling in the right vulvar region over eight months. Physical examination revealed a large cystic mass measuring approximately 15 × 10 cm involving the right vulva and inguinal area with displacement of the clitoris and vaginal introitus. Ultrasonography demonstrated a well-defined cystic lesion with internal echoes, while magnetic resonance imaging revealed a hemorrhagic cystic lesion along the course of the canal of Nuck without peritoneal communication. Surgical exploration identified a cystic mass adjacent to the round ligament containing characteristic “chocolate-like” fluid. Complete excision of the lesion was performed. Histopathological examination confirmed endometrioma of the canal of Nuck. The postoperative course was uneventful, and the patient remained asymptomatic with no evidence of recurrence during a 3-year follow-up.

Although rare, canal of Nuck endometriosis should be considered in the differential diagnosis of inguinal or vulvar masses in women of reproductive age. Early recognition, appropriate imaging and complete surgical excision allow accurate diagnosis and excellent outcomes. This case highlights an unusually large presentation and emphasises the diagnostic challenges associated with atypical clinical features. Similar content being viewed by others

None. Open access I confirm that I understand BMC Women’s Health is an open access journal that levies an article processing charge per articles accepted for publication. By submitting my article I agree to pay this charge in full if my article is accepted for publication. Dual publication The results/data/figures in this manuscript have not been published elsewhere, nor are they under consideration (from you or one of your Contributing Authors) by another publisher. Authorship I have read the Nature Portfolio journal policies on author responsibilities and submit this manuscript in accordance with those policies. Third party material All of the material is owned by the authors and/or no permissions are required. Funding This research did not receive funding. Author information Authors and Affiliations Corresponding author Ethics declarations Ethics approval and consent to participate Ethical approval was obtained from the Institutional Review Board of King Saud University Medical City. Written informed consent was obtained from the patient. Consent for publication Written informed consent for publication of this case report and any accompanying images was obtained from the patient. Competing interests The authors declare no competing interests. Additional information Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. Rights and permissions Open Access This article is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License, which permits any non-commercial use, sharing, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if you modified the licensed material. You do not have permission under this licence to share adapted material derived from this article or parts of it. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by-nc-nd/4.0/. About this article Cite this article Aldakhil, L.O. Giant endometrioma of the canal of nuck mimicking a vulvar mass: a rare case and narrative review. BMC Women's Health (2026). https://doi.org/10.1186/s12905-026-04497-w Received: Accepted: Published: DOI: https://doi.org/10.1186/s12905-026-04497-w