Infected Urachal Sinus Revealed by Umbilical Discharge in a Diabetic Adult: MRI Findings and Review of the Literature

Abstract: Background: Urachal remnants are embryonic leftovers that typically fade away before birth. However, in rare instances, they persist into adulthood, often staying hidden for decades until a secondary infection brings them to light. Case Report: We describe the clinical course of a 65-year-old diabetic male who presented with chronic, foul-smelling umbilical drainage. Given his history of recurrent abdominal pain, our team’s initial suspicion leaned toward a gastrointestinal origin, specifically fistulizing Crohn’s disease. However, Magnetic Resonance Enterography (MRE) shifted the diagnosis by revealing a 12 cm midline tract extending from the umbilicus to the bladder dome. These imaging features were pathognomonic for an infected urachal sinus. Conclusion: MRI stands out as a decisive tool in adult patients where urachal anomalies can mimic more common inflammatory conditions. Its high contrast resolution allows clinicians to rule out bowel involvement and map the tract accurately for definitive surgical planning.