Hydrocele of the canal of Nuck in a girl: ultrasound and MR appearance.

Hydrocele of the canal of Nuck is a rare condition in females. A small evagination of parietal peritoneum forms the canal of Nuck. Failure of complete obliteration of the canal results in either an indirect inguinal hernia or a hydrocele of the canal of Nuck. We present a case in a 7-year-old girl. On ultrasound, there was a comma-shaped cyst with the tail directed cranially toward the inguinal canal. The cyst had no internal echoes and demonstrated increased through transmission. Coronal and axial MR showed a thin walled cystic mass.