Focal xanthogranulomatous pyelonephritis in adulthood.

In adults with xanthogranulomatous pyelonephritis (XGP) focal involvement occurs in 17% Of patients and the remainder have diffuse involvement of the kidney. Most patients are in the fourth and fifth decades. There appears to be a predilection for the left kidney, and 60% of patients will have a positive urine culture. Radiographically, a poorly-functioning, hypovascular renal mass is seen. The clinical and pathological presentations of focal XGP can closely resemble clear-cell renal cell carcinoma, but partial nephrectomy is the preferred treatment for this inflammatory disorder. We discuss three adults with focal XGP who have been treated at The Johns Hopkins Hospital in the past 2 1/2 years.