Canal of Nuck hernias are rare and occur in female children. They are caused by a failure of complete obliteration of the canal of Nuck with a connection to the peritoneal cavity and transmitted intra-abdominal contents (e.g. bowel, omentum, fluid, ovary, Fallopian tube and/or urinary bladder).
Ultrasound is the preferred first-line modality in the evaluation of inguinal masses.
Canal of Nuck hernias typically present as an inguinal mass that can extend to labia majora. The direct continuation of the herniated contents with the peritoneal cavity is the hallmark of a hernia 1. A herniated ovary should be differentiated from other possible herniated contents by its shape being soft tissue structures containing follicles and the presence of vascular pedicle. Canal of Nuck hernias account for ~45% of hernias containing ovaries 3. Identification and examination of the ovarian pedicle with color Doppler examination is mandatory to exclude the possibility of ovarian torsion 1.
Treatment and prognosis
The risk for ovarian torsion is increased with incarceration due to blockage of normal venous and lymphatic return from the ovary herniated into the canal of Nuck. Once diagnosed, surgery is required due to the high rate of ovarian torsion 3.
The differential diagnosis of a palpable mass in the inguinal region of a female child includes 3:
- 1. Choi KH, Baek HJ. Incarcerated ovarian herniation of the canal of Nuck in a female infant: Ultrasonographic findings and review of literature. (2016) Annals of medicine and surgery (2012). 9: 38-40. doi:10.1016/j.amsu.2016.06.003 - Pubmed
- 2. Mitchell A. Rees, James E. Squires, Sameh Tadros, Judy H. Squires. Canal of Nuck hernia: a multimodality imaging review. (2017) Pediatric Radiology. 47 (8): 893. doi:10.1007/s00247-017-3853-6 - Pubmed
- 3. Huang CS, Luo CC, Chao HC, Chu SM, Yu YJ, Yen JB. The presentation of asymptomatic palpable movable mass in female inguinal hernia. (2003) European journal of pediatrics. 162 (7-8): 493-495. doi:10.1007/s00431-003-1226-7 - Pubmed