24182              ACUTE SEGMENTAL PURULENT PYELONEPHRITIS

The patient was a 72-year old diabetic woman who was admitted with left lower lobe pneumonia. She died when she became anuric with a gram negative septicaemia.

The specimen shows on the anterior surface of the kidney a triangular area 6 x 6 x 5 cms in the lower pole in which the cortical surface is haemorrhagic and contains a number of pinhead abscesses. Closer to the renal hilum there is a large triangular abscess 3 x 3 x 2 cms. The remainder of the cortical surface is hyperaemic and slightly granular. On the cut surface the involved area is haemorrhagic and there is early necrosis in the papillary region with pus formation in the surrounding minor calyces. Histology shows mild old focal fibrosis and acute purulent pyelonephritis. Apart from this many glomeruli show focal sclerosis of capillary loops and hyaline degeneration of many afferent arterioles. K-W nodules are not evident.