Adrenal Diagnostics: An Endocrinologist's Perspective focused on Hyperaldosteronism

The era of sophisticated high resolution imaging with the consequent identification of previously unrecognised adrenal masses (adrenal incidentalomas), has emphasised the need for an appropriate biochemical approach to define adrenal function. The focus of this testing is on catecholamines from the adrenal medulla (testing that has been rendered relatively straightforward by plasma metanephrine measurements) and the physiological corticosteroids, cortisol and aldosterone, synthesised by the adrenal cortex. The diagnosis of hypercortisolism remains a challenge and has been extensively reviewed. In the context of hypertension and an adrenal incidentaloma, the exclusion of hyperaldosteronism has an importance beyond simple blood pressure control. This review focuses on the recommended approaches to both the diagnosis of hyperaldosteronism and the characterisation of its aetiology. Monogenetic causes of mineralocorticoid hypertension are discussed as are recent developments with respect to both the molecular aetiology and the differential diagnosis of aldosterone-producing adenomas.