Xanthogranulomatous pyelonephritis: a rare presentation of disbelieved renal cell cancer recurrence after nephron-sparing surgery.

Xanthogranulomatous pyelonephritis is a rare, painful inflammatory subtype of chronic renal infection, which can lead to severe parenchymal destruction. It imitates virtually every other renal inflammatory disease. We report a 51-year-old male presenting with left flank pain, on evaluation found to have a renal mass with a history of nephron-sparing surgery in the same kidney performed 6 months previously. Radical nephrectomy was carried out and histopathology was suggestive of xanthogranulomatous pyelonephritis rather than renal cell cancer recurrence.