Idiopathic granulomatous nephritis in a patient with hypertension and an atrophic kidney

A patient with hypertension and an abnormal urinalysis was found on intravenous pyelography to have a small nonfunctioning left kidney. An arteriogram showed no renal artery stenosis but the renal vein renin from the small kidney was four times higher than that from the right kidney. A left nephrectomy was performed and the left kidney was found to be infiltrated with noncaseating granulomas. There was no evidence of a systemic granulomatous disease. 2 similar cases are cited. Idiopathic granulomatous nephritis is an apparently rare condition whose relationship to other granulomatous diseases is unclear.