Xanthogranulomatous pyelonephritis in pediatric patients: case report and review of literature.

Xanthogranulomatous pyelonephritis (XPN) is an unusual and rare form of chronic renal suppuration. XPN is often mistaken for renal malignancy; hence nephrectomy is commonly performed and the diagnosis confirmed by histopathology. Recent advances in imaging have allowed the radiological features to be characterized, such that routine nephrectomy is avoided. Approximately 240 cases of XPN have been reported in children. We report a 17-year-old female who presented with a 2-month history of increasing abdominal pain and intermittent episodes of increased frequency and dysuria. Plain antero-posterior radiograph of the abdomen revealed a left staghorn calculus. Computed tomography scan with intravenous contrast revealed a low-density inflammatory area and reduced cortical dye uptake on the left renal parenchyma as compared to the opposite side. A dimercapto-succinic acid renal scan revealed that the affected kidney contributed 18% of differential function. A diagnosis of XPN was made. The patient underwent percutaneous nephrostomy tube placement in an attempt to salvage the kidney. The patient eventually failed conservative management. Our review of the literature suggests that medical management has worked in some focal XPN cases, but has not been sufficiently tested in diffuse XPN.