Renal pelvis rupture in a kidney with ureteropelvic junction obstruction and extrarenal calyces.

The extrarenal calyx (ERC) is a rare congenital anomaly, associated with various other abnormalities of the urogenital system. We report a unique case of ERC in a solitary functioning kidney with a massively dilated pelvis that developed spontaneous rupture. A dismembered pyeloplasty was performed at the time of rupture. The patient did well post-operatively with a stable creatinine and stable SFU grade 2 hydronephrosis.