Solitary intrarenal cyst: correctable cause of hypertension.

A patient with hypertension was found to have a solitary renal cyst in his right kidney. Peripheral plasma renin activity was elevated following furosemide challenge, and there was increased renal vein renin activity on the affected side with suppression of renin secretion from the contralateral kidney. Percutaneous aspiration of the cyst and injection of a sclerosing contrast medium was associated with a sustained decrease in blood pressure.