Adrenal tumours and subclinical adrenal hyperfunction

Abstract

There is a significantly higher prevalence of obesity, hypertension, impaired glucose metabolism, and dyslipidaemia in patients with adrenal incidentalomas. The role of excess adipose tissue in the pathogenesis of adrenal adenomas has not been explored in depth. The study reviews the knowledge about different mechanisms that are related to adrenal tumourigenesis and steroidogenesis. The next objective of this paper is to provide an overview of subclinical types of adrenal hormonal hyperfunction. Recent research has challenged the bimodal diagnosis of hypercortisolism and primary hyperaldosteronism as categorical diseases. Currently we know that milder and subclinical forms are very common, and their involvement in cardiovascular disease is well characterised. Mild autonomous cortisol secretion and mild primary aldosteronism lead to the development of hypertension and metabolic disturbances. The clinical picture of pheochromocytoma is extremely variable and depends on the synthesis and release of catecholamines. The term "subclinical" does not apply fully to pheochromocytoma. In this case, it would be appropriate to describe the tumour as clinically silent. In addition, the term "biochemically silent" is used, based on biochemistry, when plasma and urinary metanephrine levels are below the upper cut-offs of the reference intervals.

Keywords: adrenal incidentaloma; mild autonomous cortisol secretion; obesity; silent pheochromocytoma; subclinical primary aldosteronism.