Part of “CHAPTER 80 – HYPERALDOSTERONISM“

Autonomous overproduction of aldosterone occurs in ˜2% of patients with hypertension and was recognized initially as being associated with either a unilateral adenoma (aldosterone-producing adenoma, or APA) or bilateral hyperplasia of the zona glomerulosa. Because patients with bilateral adrenal disease tended to have a clinical presentation similar to that of patients with an APA (hypertension and hypokalemia) and, like the patients with unilateral disease, they showed suppression of the renin-angiotensin system, they also were assumed to have a primary adrenal disorder. Subsequent observations have not proved this to be true; they suggest, instead, that bilateral hyperplasia of the zona glomerulosa probably is not a primary adrenal disorder in most cases and may have more than one cause. Unilateral adrenalectomy usually cures or ameliorates the hypertension in patients with an APA, whereas subtotal or total adrenalectomy, with few exceptions, has little effect on the blood pressure of patients with bilateral hyperplasia. In the case of those few patients who have primary adrenal hyperplasia, unilateral adrenalectomy may be curative.5 In some patients with bilateral hyperplasia, the hyper-aldosteronism was dependent on ACTH (so-called glucocorticoid-remediable hyperaldosteronism). The hypothesis that a trophic hormone, possibly of pituitary origin, may be responsible for bilateral hyperplasia not caused by ACTH has received considerable support, although it has not been definitively proved. As a result of advances in knowledge, the inclusive designation of “primary hyperaldosteronism” for those patients with hyperal-dosteronism associated with both adenoma and bilateral hyperplasia
has tended to be replaced by the more specific designations of aldosterone-producing adenoma, idiopathic hyperaldosteronism, primary adrenal hyperplasia, and glucocorticoid-remediable hyper-aldosteronism. Rarely, adrenocortical carcinoma may overproduce aldosterone. These five disorders present as hypokalemic alkalosis, hypertension, low or suppressed plasma renin activity, and high aldosterone concentrations (see Table 80-1).