Since 1974 primary
aldosteronism has been diagnosed in 71 patients in our outpatient clinic. Thirty-four patients had a unilateral
aldosterone-producing
adenoma, whereas bilateral adrenal
hyperplasia was diagnosed in 37 patients. Although at the time of diagnosis the mean
potassium values were lower and mean
aldosterone levels were higher in patients with an
adenoma, as compared to those with bilateral
hyperplasia, these 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. During the first few years, a successful differential diagnosis was made by adrenal phlebography and separate sampling of plasma
aldosterone in both adrenal veins; later non-invasive imaging techniques such as computed tomography and
radionuclide scanning were used. The best results 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
drug treatment. In contrast, patients with bilateral
hyperplasia were treated pharmacologically, but only in half of the patients could normal blood pressure values be achieved. Two thirds of the male patients developed
gynecomastia during
spironolactone treatment. As expected, unilateral
adrenalectomy was unsuccessful in the 7 patients with bilateral
hyperplasia who underwent surgery. Our results confirm that surgical treatment of adrenal
adenomas and
drug treatment of bilateral
hyperplasias are the appropriate
therapy in primary
aldosteronism. A differential diagnosis cannot be made on the basis of clinical and non-invasive laboratory data alone; imaging techniques have to be included in the diagnostic process.(ABSTRACT TRUNCATED AT 250 WORDS)