[Physiopathological and functional semeiologic considerations in a case of primary normoaldosteronemic...

Among the atypical pictures of primary aldosteronism, sometimes, normal blood and urine concentration of aldosterone have been observed in association with an adrenal aldosterone-producing adenoma. Here we report a case of atypical primary aldosteronism so characterized: -- the patient had the typical clinical findings of aldosteronism (hypertension, hypokalemic alkalosis, polyuria, etc). -- the patient exhibted all the biochemical abnormalities of primary aldosteronism: increase of exchangeable Na and of plasma volume, decrease of exchangeable K, etc. -- the patient had normal blood and urine levels of aldosterone. -- the patient's blood and urine aldosterone concentration increased following sodium depletion and K administration. Such increase was comparable with that obtained in normal subjects after the same tests. However, at the end of these tests, the patient was still in potassium depletion and sodium repletion. Therefore, it was concluded that the secretion of aldosterone, although normal in absolute values, was inappropriate to the metabolic status of the patient, since such "normal" values were found in association with conditions that should have produced an inhibition of aldosterone production. The catheterization of adrenal veins demonstrated the existence of a right adrenal adenoma. The blood pressure and the biochemical parameters of the patients have been normalized by right adrenalectomy.