25604              PYONEPHROSIS OF KIDNEY WITH STAGHORN CALCULUS

The patient was an Italian woman aged 32 who presented with a 7-day history of pain in the left loin, accompanied by fever, dysuria and dark foul-smelling urine. She had been lethargic for about 3 months. There was a past history of left renal infection. X-ray showed a staghorn calculus in the left renal pelvis and intravenous pyelogram showed poor function in the left kidney. The urine contained 2000 polymorphs/ml. A left nephrectomy was performed.

The specimen consists of half a kidney sectioned longitudinally. The kidney measures 12 cms in length. A large staghorn calculus fills the pelvis and there is marked dilatation of calyces, especially at the upper pole, where an originally pus-filled cavity measures 4 cms in diameter. There is haemorrhagic necrosis of pyramids at the lower pole. The surface of the kidney is slightly irregular. Histology shows diffuse fibrosis of the renal substance, with a chronic inflammatory infiltration composed mostly of polymorphs and macrophages, but with some admixture of plasma cells and eosinophils.