Xanthogranulomatous pyelonephritis mimicking malignant disease: is preservation of the kidney possible?

Xanthogranulomatous pyelonephritis (XGP) is an uncommon form of pyelonephritis rarely seen in children. It is characterized by destruction of the renal parenchyma and invasion of adjacent tissues, mimicking renal tumors. Preoperative diagnosis is very difficult. Two children with XGP are presented. One underwent nephrectomy and the other drainage of a renal abscess with kidney preservation. Although surgery is considered the only effective treatment, a high index of suspicion and renal biopsy may prevent radical nephrectomy.