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Xanthogranulomatous pyelonephritis. Angiographic observations made in one case at an interval of six years.

In a woman aged 67, comprehensive angiographic examination revealed an extensive renal process which had led to thrombosis of the inferior vena cava. At exploratory surgery the process seemed inoperable. The angiographic study was repeated after an asymptomatic period of 6 years and disclosed shrinking of the kidney involved. Revision of the microscopic findings altered the initial diagnosis of renal carcinoma in favour of xanthogranulomatous pyelonephritis. The observation is of interest by virtue of the characteristic angiographic findings, extension of the process to the venous system, and angiographic evidence that spontaneous regression is possible.