Xanthogranulomatous pyelonephritis is a chronic destructive granulomatous process of renal parenchyma in association with long-term urinary tract obstruction and infection.
Clinical presentation includes flank or abdominal pain, lower urinary tract symptoms, fever, palpable mass, hematuria and weight loss.
This case shows a xanthogranulomatous pyelonephritis associated with staghorn calculus and complicated with extensive retroperitoneal abscess.