Infected urachal cyst in an adult patient.

Urachal cyst is a clinical malformation caused by failure of the allantois to obliterate during embryological development. Because of its rare presentation in adults, urachal cysts are often incorrectly diagnosed. Delay in diagnosis can cause complications such as peritonitis, fistula, sepsis, or even malignant manifestation. We report the case of a 19-year-old adult male, who presented with clinical features mimicking appendicitis. Ultrasound and magnetic resonance imaging confirmed diagnosis of an infected urachal cyst, which was treated surgically.