A case of renovascular hypertension with high urinary noradrenaline excretion

A case report of 32-year-old male with renovascular hypertension, suspected to be pheochromocytoma as a result of a tentative diagnosis, is given. The suspicion was based on the observation of high levels of urinary noradrenaline on several occasions with the sign of hyperreninemia. Reduction of the urinary noradrenaline levels by the administration of angiotensin converting enzyme inhibitor (SQ-14225) suggested that the high urinary noradrenaline probably resulted from hyperreninemia which reflected high plasma levels of angiotensin II. Radioisotope renography and intravenous urography strongly suggested a reduction of the right renal blood flow, and the final diagnosis of renovascular hypertension was obtained on the basis of renal arteriography. On the other hand, the possibility of a catecholamine releasing tumor was carefully excluded by angiography before undertaking surgical treatment. The affected kidney was transplanted autogenously into the abdominal cavity. The successful operation led to a decrease in plasma renin activity, blood pressure and urinary noradrenaline excretion. In the present case, we were thus unable to define at first whether the primary genesis of hypertension was related to the hyperactivity of the renin-angiotensin system caused by renovascular stenosis or a noradrenaline releasing tumor.