Aldosterone-producing adenoma and other surgically correctable forms of primary aldosteronism

This review deals with the prevalence, presentation, diagnosis and management of surgically correctable forms of primary aldosteronism (PA).PA is also called primary hyperaldosteronism. Surgically correctable forms of the condition are characterized by unilateral aldosterone hypersecretion. They include aldosterone-producing adenoma, also termed Conn's adenoma or aldosteronoma; aldosterone-producing carcinoma, a very rare condition; and primary unilateral adrenal hyperplasia, a condition with a unilateral aldosterone hypersecretion documented by adrenal vein sampling (AVS) but without a typical adenoma. In contrast, idiopathic adrenal hyperplasia and familial hyperaldosteronisms type 1 and 2, in which aldosterone hypersecretion is bilateral, are not surgically correctable. The subtypes of PA are presented in Table 1.Hyperaldosteronism is a condition caused by the overproduction of aldosterone, and is characterized by sodium retention and potassium excretion with resultant hypertension and hypokalemia. The condition was first described by J Conn [1], who further distinguished primary and secondary hyperaldosteronism on the basis of plasma renin levels, PA being characterized by renin suppression [2]. In a recent clinical practice guideline, PA was defined as "a group of disorders in which aldosterone production is inappropriately high, relatively autonomous from the renin-angiotensin system, and non-suppressible by sodium loading" [3].The prevalence of PA and its various surgically correctable subtypes in adults is not known. The prevalence of a raised aldosterone to renin ratio in the general population [4] (Figure 1) and in hypertensive patients referred to specialized centers [5-9] is high (Table 2), but a raised ratio is not sufficient for diagnosing PA (see [3] and the Diagnosis section below). In referral samples involving more than 1,000 hypertensive patients [5-10], the prevalence of a raised aldosterone to renin ratio ranged from 6.4 to 22.8%: 5.9 to 11.3% o