Infected Urachal Cyst Presenting as a Huge Abdominal Abscess in an Elderly: A Case Report.

Urachal anomalies are rare congenital disorders in which an embryonic vestige of the allantois persists after birth as a tubular remnant. These urachal remnants may present with various clinical conditions that are mainly detected during infancy and childhood but are exceedingly rare in adulthood. We report a rare case of a 63-year-old man with a history of recurrent purulent umbilical discharge who presented with painful swelling and erythema of the periumbilical area, accompanied by fever, suggesting an intra-abdominal or abdominal wall abscess on physical examination. Abdominal computed tomography and magnetic resonance imaging revealed a large urachal cyst abscess. As the patient required repeated percutaneous drainage procedures because of abscess recurrence, radical en bloc excision of the urachal remnant was subsequently performed via an open approach, with good outcomes. This case emphasizes the clinical importance of considering complicated urachal disorders, such as infected urachal cysts, in the differential diagnosis of acute abdominal pain in adults, as well as the role of primary percutaneous drainage in the initial management of large abscesses. We also highlight the need for subsequent complete excision of the urachal remnant, which may help prevent recurrent infections and abscess formation and reduce the potential risk of malignant transformation, particularly in adulthood.