Encysted hydrocele of the canal of Nuck- A rare cause of inguinal swelling in an adult female: A case report

Abstract

Introduction and importance: Hydrocele of the canal of Nuck, a rare developmental anomaly caused by incomplete obliteration of the processus vaginalis, mimics male spermatic cord hydrocele. Its adult presentation remains underrecognized, often misdiagnosed as inguinal hernia or cysts.

Case discussion: A 23-year-old woman presented with a 2-month history of painless right inguinal swelling. Ultrasonography and contrast-enhanced CT demonstrated a non-communicating cystic lesion in the canal of Nuck, confirmed surgically as an encysted hydrocele adjacent to the round ligament. Histopathology corroborated a mesothelial-lined cyst. Open excision with high ligation was performed, achieving complete resolution without recurrence at 6 months.

Discussion: Hydrocele of the canal of Nuck (incidence: 0.76 % in young females of age < 12 years), presents as painless inguinal swelling. Embryologically, failed closure creates a cystic space, often encysted (non-communicating), mimicking spermatic cord hydroceles. Ultrasound identifies anechoic lesions; MRI/CT clarifies ambiguous cases. Though 33 % associate with hernias, this case lacked one, emphasizing diagnostic vigilance. Surgical excision with high ligation is definitive; laparoscopy, while advantageous, risks complications, favoring open approaches in non-communicating types.

Conclusion: Encysted canal of Nuck hydrocele, though rare in adults, should be considered in women with inguinal swelling. Diagnosis relies on ultrasonography and CT, and definitive treatment is achieved with open excision and high ligation.

Keywords: Canal of Nuck; Case report; Hydrocele; Processus vaginalis; Surgical excision; Ultrasonography.