Hydrocele of the Canal of Nuck Mimicking Inguinal Hernia in an Adult Woman: Ultrasound and Magnetic Resonance Imaging (MRI) Correlation.

A 29-year-old woman presented with right-sided inguinal swelling associated with intermittent pain for 1.5 years. Ultrasound examination demonstrated tubular anechoic cystic lesions within the right inguinal canal extending toward the labium majus, with minimal posterior acoustic enhancement, partial compressibility, and no internal vascularity on Doppler imaging. Magnetic resonance imaging (MRI) revealed an elongated cystic lesion measuring approximately 6.3×2.2 cm, extending from the deep inguinal ring through the superficial inguinal ring to the right labium majus. The lesion was hyperintense on T2-weighted and short tau inversion recovery (STIR) sequences and hypointense on T1-weighted images, with thin internal septations and no definite communication with the peritoneal cavity. Based on the clinical and characteristic multimodality imaging findings, a diagnosis of hydrocele of the canal of Nuck was made. This case demonstrates the imaging features of this uncommon cause of female inguinal swelling and its differentiation from an inguinal hernia.