Normokalemic Primary Aldosteronism

Abstract

We have reported that the combination of overproduction of aldosterone and suppression of plasma renin activity is uniquely diagnostic of an aldosterone-secreting adrenal cortical tumor.^1-3 These diagnostic criteria were established initially by demonstration of their existence preoperatively in ten consecutive patients from whom aldosterone-secreting adrenal cortical adenomas were subsequently removed surgically.⁴ All ten of those patients had exhibited hypokalemic alkalosis preoperatively and, thus, satisfied what we had previously regarded as a biochemical aberration necessary for diagnosis of primary aldosteronism. For numerous reasons, discussed in detail in previous publications,^2-4 we had become suspicious that hypokalemia was a manifestation of severe and prolonged primary aldosteronism, and that most patients with this disease were maintaining normal levels of serum potassium. Such patients would then be clinically indistinguishable from patients with "essential" hypertension. We had also become impressed with the gross and histological similarities between the aldosterone-secreting adenomas that we had