Renal calyceal rupture is due to the increase in pressure within an obstructed pelvicalyceal system, with ureteric calculi being the most common culprit.1
In this patient, there was lower pole calyceal rupture with urine leak into the retroperitoneum forming a urinoma. Although this diagnosis may be highly suggestive on plain scan alone, contrast and delayed excretory scans are useful to demonstrate and confirm the site of urine leak as well as to differentiate it from other fluid collections.