Metachronous emphysematous pyelonephritis and xanthogranulomatous pyelonephritis in the contralateral kidney: an extremely rare condition.

Received April 2007 Accepted August 2007 INTRODUCTION Emphysematous pyelonephritis is an uncommon and severe acute bacterial infection of the kidney. Diagnosis is usually made very late due to changing manifestations and infrequent occurrence. On the other hand, xanthogranulomatous pyelonephritis is a rare severe renal infection which typically results in diffused destruction of the kidney in a chronic course. It has been reported that the peak incidence of the disease is between the 4th and 6th decades of life.(1) Nonfunctioning kidneys in xanthogranulomatous pyelonephritis have been reported in 50% to 70% of cases, and in 22% to 70%, nephrolithiasis has been an associated finding.(1) According to radiological backgrounds, the disease can mimic the features of a renal tumor. Therefore, nephrectomy is the treatment of choice.(1) I report a metachronous occurrence of emphysematous pyelonephritis and xanthogranulomatous pyelonephritis in the contralateral kidney. CASE REPORT A Saudi 50-year-old woman with confirmed diagnoses of diabetes mellitus, hypertension, chronic liver disease, and end-stage renal disease (ESRD) was admitted to the emergency room. Her chief complaint was right loin pain and fever for the past 2 weeks. Urinary symptoms were absent. Three years earlier, the diagnosis of atrophic nonfunctioning right kidney had been made for her with a suspicion of left renal tumor (Figure 1). Left partial nephrectomy had been performed and the histological evaluation had turned out to be xanthogranulomatous pyelonephritis (Figure 2). Five months after the operation, the patient was