Hydrocele of the canal of Nuck mimicking an inguinal hernia in a 34-year-old pregnant woman: a case report.

Hydrocele of the canal of Nuck (HCN) is a rare condition in females that commonly presents in infancy and early childhood. It occurs when fluid accumulates within a patent part of the processus vaginalis causing a swelling in the groin. Clinicians would typically not consider it while evaluating inguinal swellings in adult females. Consequently, patients are likely to remain undiagnosed until complications set in. Herein, we present a clinically rare case of HCN in a pregnant adult female. We also aim to report how easily the diagnosis was missed, and to remind the medical community of other likely causes of inguinal swelling that could mimic an inguinal hernia. We managed a gravid 34-year-old university graduate with a spontaneous swelling on the left inguinal region. The swelling was a painless, firm, irreducible mass of 3 months' duration. She was gravida 1, para 0, in her first trimester. There was no associated symptom. Abdominal ultrasound scan found a well-defined mass of size 2.30 x 3.88cm around the left Hesselbach's triangle containing homogenous fluid, with minimal vascularity on colour Doppler interrogation. The working diagnosis was irreducible left inguinal hernia in a pregnant woman. This was later discovered to be a misdiagnosis. She was booked for inguinal herniorrhaphy, but HCN was found intraoperatively. Diagnosis of HCN is a challenge as it is seldom made on the basis of clinical findings alone. A high index of suspicion should be entertained by clinicians for early diagnosis and appropriate management.