The CT features are most consistent with xanthogranulomatous pyelonephritis complicated by an abscess formation extending to the perinephric space.
Xanthogranulomatous pyelonephritis (XGP) is a rare form of chronic pyelonephritis and is a granulomatous disease that results in a non-functioning kidney.
Xanthogranulomatous pyelonephritis with abscess formation
