Visualizing the "Pop-Off": Point-of-Care Ultrasound Diagnosis of Spontaneous Ureteral Rupture.

Spontaneous ureteral rupture (SUR) is an uncommon complication of obstructive uropathy and may mimic other acute abdominal conditions. We report a case of a 66-year-old man who presented with sudden severe right flank pain and a deceptively normal urinalysis. Point-of-care ultrasound (POCUS) revealed mild right hydronephrosis and a large anechoic perinephric fluid collection that provided an acoustic window, allowing direct visualization of a focal discontinuity in the proximal ureter. Contrast-enhanced computed tomography (CT) confirmed ureteral rupture with extensive urinoma formation secondary to a distal ureteral calculus. The patient underwent urgent urinary diversion via percutaneous nephrostomy followed by double-J stenting and recovered fully. This case highlights the diagnostic utility of POCUS in identifying extrarenal collections and, in rare instances, the rupture site itself. While POCUS can expedite evaluation, definitive diagnosis requires delayed-phase CT, particularly when perinephric fluid mimics intraperitoneal free fluid or when urinalysis is non-contributory.