Abstract
Xanthogranulomatous pyelonephritis (XGP) is a chronic pyelonephritis observed in children and exceptionally in infants. Symptomatology is vague and may delay diagnosis and patient's management. Treatment is based on medical therapy but most often on surgery with poor renal prognosis. We report the case of a 15-month old infant with isolated mass in the left flank. He had no fever or alteration of general state and urine cultures were sterile. Radiological evaluation (renal ultrasound, uroscan and renal scintigraphy) highlighted left non-functioning kidney with "hydropyonephrosis" evoking the diagnosis of XGP. The indication for total nephrectomy by lombotomy was posed and definitive anatomo-pathological examination confirmed the diagnosis of diffuse XGP. This observation emphasizes the importance of suspect PXG in patients with renal mass or malformative uropathy with recurrent urinary tract infections whose treatment should be rigorous and codified.