Chronic nephrotic syndrome and chronic renal failure by amyloidosis secondary to xanthogranulomatous pyelonephritis

The association of xanthogranulomatous pyelonephritis (XPN) and systemic amyloidosis is extremely rare. This association has been described in only six cases. We present a 4-year-old male admitted with a history of anuria and abdominal pain. Investigations revealed multiple calculi in both kidneys. A right pyelolithotomy and left nephrectomy were performed. Histological examination demonstrated XPN and amyloidosis. At discharge serum creatinine had dropped to 1.1 mg/dl but after being lost to follow up for 9 years, the child was readmitted because of edema. Laboratory examination revealed a nephrotic syndrome and serum creatinine of 2.3 mg/dl. Rectal biopsy showed the presence of amyloid. A treatment by colchicine was unsuccessful. Fifteen months later, at the age of 15 years, the patient developed terminal renal failure (serum creatinine 14 mg/dl).