Renal matrix stones in an emphysematous pyelonephritis.

A 74-year-old-woman was referred to our hospital for further examination. Her chief complaint had been a high-grade fever, but she was seen at our hospital without fever. Plain fi lm of kidney, ureter and bladder drip infusion pyelography and abdominal computed tomography (CT) showed a gas shadow surrounding calcifications in the right renal pelvis. We diagnosed right emphysematous pyelonephritis. Since changes in the CT findings were not remarkable for 2 weeks, we performed laparoscopic right nephrectomy, even though her condition had not worsened. The renal pelvis contained brownish and clayish matter. We report here this rare case of renal matrix stones.