Incidental discovery of an infected urachal diverticulum mistaken for an umbilical hernia: a case report.

Urachal diverticulum is the rarest form of urachal anomalies, accounting for ˂5% of cases. It results from incomplete obliteration of the internal end of the urachus, forming a blind internal fistula communicating with the bladder. It is usually asymptomatic but may become complicated by infection. We report the case of a 4-year-old boy admitted for a painful umbilical swelling, clinically diagnosed as a strangulated umbilical hernia. During the procedure, a tubular structure attached to the umbilicus was identified and dissected; it was found to communicate with the bladder dome, consistent with an infected urachal diverticulum. The diverticulum was resected at its vesical base, followed by a three-layer cystorrhaphy. The postoperative course was uneventful. This case highlights the diagnostic challenge posed by infected urachal diverticulum, which can mimic common surgical emergencies such as umbilical hernia. Preoperative imaging and awareness of this rare entity are essential to avoid diagnostic errors.