PRIMARY ALDOSTERONISM - DIFFERENCE IN CLINICAL PRESENTATION AND LONG-TERM FOLLOW-UP BETWEEN ADENOMA AND BILATERAL HYPERPLASIA OF THE ADRENAL-GLANDS

Since 1974 primary aldosteronism has been diagnosed in 71 patients in our outpatient clinic. Thirty-four patients had a unilateral aldostero ne-producing adenoma, whereas bilateral adrenal hyperplasia was diagno sed in 37 patients. Although at the time of diagnosis the mean potassi um values were lower and mean aldosterone levels were higher in patien ts with an adenoma, as compared to those with bilateral hyperplasia, t hese laboratory data did not allow us to differentiate between the two leading causes of primary aldosteronism in the individual patient due to pronounced overlap of laboratory values between the two groups. Du ring the first few years, a successful differential diagnosis was made by adrenal phlebography and separate sampling of plasma aldosterone i n both adrenal veins; later non-invasive imaging techniques such as co mputed tomography and radionuclide scanning were used. The best result s were obtained in patients with adenoma who underwent adrenalectomy. Fifty-six percent of these patients were clinically and biochemically cured; 28% were improved and had normal blood pressure values during d rug treatment. In contrast, patients with bilateral hyperplasia were t reated pharmacologically, but only in half of the patients could norma l blood pressure values be achieved. Two thirds of the male patients d eveloped gynecomastia during spironolactone treatment. As expected, un ilateral adrenalectomy was unsuccessful in the 7 patients with bilater al hyperplasia who underwent surgery. Our results confirm. that surgic al treatment of adrenal adenomas and drug treatment of bilateral hyper plasias are the appropriate therapy in primary aldosteronism. A differ ential diagnosis cannot be made on the basis of clinical and non-invas ive laboratory data alone; imaging techniques have to be included in t he diagnostic process. The long-term clinical outcome was more favorab le in patients with an adrenal adenoma that can be removed surgically than in patients with idiopathic hyperplasia of both adrenal glands.