Xanthogranulomatous pyelonephritis in children and adults.

Sixteen patients with xanthogranulomatous pyelonephritis (XGP) are reported. The preoperative diagnosis of XGP may be difficult because of its clinical and radiological similarities to various other renal lesions, but in four patients XGP was suspected pre-operatively. Nephrectomy is necessary in most patients, although medical treatment may help a few.