Xanthogranulomatous pyelonephritis with associated renal cell carcinoma

Xanthogranulomatous pyelonephritis is associated with obstruction, stones and infection. CT is the mainstay of diagnosis, but appearances can mimic other conditions, including renal cell carcinoma. Nephrectomy is commonly recommended, but conservative treatment with antibiotics has been described after tissue diagnosis. We present a case of xanthogranulomatous pyelonephritis with concomitant renal cell carcinoma, which was an association that was suggested in 1988 and supported by subsequently reported cases. Conservative management of biopsy or cytology proven xanthogranulomatous pyelonephritis is unsafe, as an area of synchronous malignant tumour may be missed: we recommend it only in patients unfit for nephrectomy.