[Refractory urinary tract infections: diagnosis and treatment of xanthogranulomatous pyelonephritis]

Xanthogranulomatous pyelonephritis (XGP) is a rare inflammatory condition of the renal parenchyma that is associated with long-term partial obstruction and infections of the urinary tract. Because its symptoms can be non-specific, a diagnosis is often made with delay.

We describe 2 patients with frequently recurring urinary tract infections and urinary tract infections that were difficult to treat. Imaging studies unmasked a diffusely enlarged kidney and renal stones, leading to the diagnosis of xanthogranulomatous pyelonephritis. Both female patients were treated successfully by draining the affected kidney by means of a ureteral double-J catheter along with antibiotic treatment.

Imaging studies are important in patients with recurrent pyelonephritis or persistent pyelonephritis despite adequate antibiotic treatment; urinary tract obstructions and complications of pyelonephritis such as XGP can then be identified. When XGP is adequately treated by antibiotics and drainage of the affected kidney this can sometimes prevent having to perform a nephrectomy.