Idiopathic Spontaneous Rupture of Renal Pelvis in a Single Functioning Kidney.

Spontaneous rupture of renal pelvis (SRRP) is a rare condition resulting in an extravasation of urine into retroperitoneal space. Due to the uncharacteristic symptoms, often mimicking renal colic, its diagnosis may be complicated. Herein, we report a case of a 73-year-old male with a solitary functioning kidney who presented with malaise and right-sided abdominal pain, rapidly followed by anuria. Laboratory tests showed the signs of AKI. Contrast-enhanced CT performed soon after the admission showed nonspecific abnormalities in the right middle abdomen suspected to be either inflammatory infiltration or surgical scarring. Symptomatic treatment was started, and an acute hemodialysis treatment was commenced. After a temporal improvement, the patient's general condition worsened significantly, with exacerbated pain and massive increase in plasma creatinine. A second contrast-enhanced CT was performed with an addition of urography phase, revealing the extravasation of the contrast media in the location suggesting the rupture of the renal pelvis. The patient was treated successfully by the placement of a double-J ureteral stent into the ureter. Usually, a clear etiology of SRRP can be determined, that is, urinary tract obstruction, but in this case, we could not find a definite cause. It is important to remember that in the presence of a nonspecific abdominal pain and laboratory signs of AKI, a rare cause like SRRP should be taken into consideration. Performing a contrast CT scan with urography phase can save time in establishing a diagnosis and enable immediate urological intervention.