Primary Megaureter Unmasked by Imaging for Trivial Abdominal Trauma: A Case Report

Abstract

Background: Occult preexisting renal lesions are often discovered incidentally during evaluation of patients for unrelated conditions. This case report aims to highlight how imaging for trauma can expose a silent organ-threatening congenital anomaly of the urinary tract. Case Presentation: A 13-year-old boy presented to the emergency department a week after being hit on his abdomen with a plywood during play. He reported left flank pain that has worsened over time. His past medical and surgical history was unremarkable. He was hemodynamically stable, and abdominal examination revealed mild left flank tenderness. An initial abdominal ultrasound scan revealed severe left hydroureteronephrosis. Dipstick urinalysis showed 3+ blood, while CT urogram revealed a markedly enlarged left kidney, measuring 18cm in its bipolar length, with cortical thinning and an ipsilateral tortuous hydroureter that tapered distally. Severe hydroureteronephrosis secondary to a primary obstructive megaureter was diagnosed. He underwent left distal ureteric exploration and ureteric reimplantation with intraoperative findings of a severely dilated and redundant left ureter with an area of narrowing at the distal end. He recovered uneventfully. Conclusion: The incidental discovery of a primary megaureter during trauma imaging is a reminder that acute presentations can unmask chronic, organ-threatening conditions. Therefore, this case report underscores the need for clinicians to comprehensively review trauma imaging beyond the immediate context of injury.