Spontaneous Rupture of a Hydronephrotic Kidney Secondary to Congenital Ureteropelvic Junction Obstruction: A Report of a Rare Case.

Spontaneous rupture of the pelvicalyceal system due to obstructive uropathy is a rare urological emergency. It can mimic other abdominal catastrophes and may be underrecognized, especially in young patients. We report the case of a 17-year-old male presenting with sudden-onset left flank pain, fever, and vomiting. Imaging revealed a grossly dilated left pelvicalyceal system with contrast extravasation into the perinephric space, consistent with spontaneous rupture secondary to ureteropelvic junction (UPJ) obstruction. The patient was managed surgically via open Anderson-Hynes pyeloplasty with successful resolution. This case highlights the importance of early recognition and surgical management of spontaneous renal rupture in the context of UPJ obstruction. High clinical suspicion, timely imaging, and prompt intervention are crucial to prevent morbidity.