FOCAL XANTHOGRANULOMATOUS PYELONEPHRITIS PRESENTING AS A RENAL TUMOR WITH VENA CAVAL THROMBUS

A 50-year-old man presented with right flank pain and Escherichia coli urosepsis, which was treated with intravenous antibiotics. Excretory urography revealed a 4 cm. mass in the right kidney without nephrolithiasis. Abdominal computerized tomography and magnetic resonance imaging confirmed a 5 X 6 x 9 cm. necrotic mass in the upper pole of the right kidney with a thrombus in the renal vein extending into the infrahepatic vena cava (fig. 1). Due to the vena caval thrombus malignancy was suspected, and right transabdominal radical nephrectomy was performed. After arterial ligation the thrombus did not appear to involve the vena cava and the renal vein was transected at its ostium. The 15.5 X 10.8 x 7.2 cm. kidney weighed 480 gm. An indurated area was palpated a t the hilum. The ureter was