Xanthogranulomatous pyelonephritis masquerading as a tumor in an infant.

Xanthogranulomatous pyelonephritis (XGP) is an uncommon form of chronic pyelonephritis and a well recognized entity. It is rarely seen in children and neonates. The preoperative diagnosis is difficult and the etiology is still obscure. The condition is mostly diagnosed on nephrectomy specimen. The focal form mimicking neoplastic condition is rare. A case of XGP is reported here in an 8 month old child in which case nephrectomy was done with the clinical diagnosis of malignant renal tumor. Various modalities of preoperative diagnosis of this entity with conservative approach are also discussed.