Purpose or Case Report: The canal of Nuck, described by Anton Nuck in 1691, is an evagination of peritoneum into the labia majora and represents a patent processus vaginalis in females. While it usually undergoes obliteration soon after birth, it may be complicated by the accumulation of fluid (female hydrocele), or herniation of the bowel, the adnexa or the uterus into this potential space.We discuss the embryology of the Canal of Nuck and the various complications that may arise in infants and young girls with a patent canal.
Methods & Materials: A list of patients seen at our institution between 2006 and 2016 with a patent Canal of Nuck was obtained based on a record search in the computerized Radiology Information System (RIS) . The clinical presentation leading to diagnosis as well as the diagnostic imaging findings of these patients were reviewed and will be presented. The embryologic origin of the Canal of Nuck will be illustrated.
Results: Twenty one patients (mean age 2 years, range 1 month-19 years) were identified. The diagnosis was made by ultrasound in 18 patients, all of whom were evaluated for inguinal or labial mass with or without pain. In the remaining three patients, a canal of Nuck was noted as an indicidental finding on CT(2 patients) and MRI(1 patient) . Of the 21 cases, four patients with unilateral female hydroceles. Nine patients had herniation of a viable left ovary and three patients had herniation of a viable right ovary into the canal. One had a torsed nonviable ovary in the canal while another had a partially torsed ovary with a large hemorrhagic cyst.Two patients had herniation of the ovary as well as a portion of the uterus and fallopian tube into the canal. One had patency of both the right and left canal with herniation of bowel into one canal and a hydrocele into the contralateral canal.
Conclusions: Complications due to a persistent Canal of Nuck are uncommon.Recognition of this anatomic variant and its potential complications is important to pediatric radiologists who may be asked to to evaluate a patient with a labial mass.