A rare case of left Nuck’s canal cystic endometriosis: Computed Tomography findings

Introduction: Endometriosis is a common and chronic gynaecological condition but the implant in the canal of Nuck constitutes a very unusual state with an estimated prevalence of 0.3%–0.6% of all endometriosis cases. The canal of Nuck is an abnormal patent pouch of parietal peritoneum extending anteriorly from the round ligament of the uterus into the labia majora, thus represents a communication between the peritoneal cavity and the female inguinal canal. This condition may permit the seeding of endometriotic tissue in the inguinal soft tissues, becoming a possible cause of inguinal swelling or pain. Case description: A 43-years-old woman presented with painful swelling in her left groin. Ultrasound and a subsequent pelvic computed tomography showed a cystic lesion as for a Nuck’s canal encysted hydrocele. The patient underwent an anterior open surgery and the histologic examination revealed an endometrium-like tissue in the cystic wall. Conclusion: In women presenting with painful swelling of the groin, despite its rarity, endometriosis of the Nuck’s canal must be differentiated from other more common pathologies like hernias, varicoceles, neoplasms, and lymphadenopathies. Imaging can aid in differential diagnosis, but the final diagnosis is entrusted to histology, which enable to exclude an underlying malignancy.