Atypical presentation of focal xanthogranulomatous pyelonephritis

Xanthogranulomatous pyelonephritis (XGP) is a chronic condition caused by granulomatous reaction to chronic renal infection. The diffuse form is more common where the kidney is enlarged while still retaining the reniform shape. The focal form is very rare and is pathologically similar to diffuse form but limited to one pole or less. To the best of our knowledge, all reported cases of XGP in the literature report a history of chronic obstructive uropathy such as calculus, stricture, or mass. We are presenting here a case report of focal XGP in a 58-year-old woman with no known history of obstructive uropathy and presented with nonspecific symptoms.