Primary Hyperaldosteronism: Pitfalls in the Diagnosis and a not so Peculiar Evolution - Case Report

Abstract

Primary hyperaldosteronism is now assumed to account for 10-15% of all cases of non selected high blood pressure. The differential diagnosis between bilateral hyperplasia and unilateral adenoma remains however a medical challenge, and the pathogenic stimulus for hyperplasia is still unknown. HS, a female patient aged 32, presented with High Blood Pressure and hypokalemia. An elevated aldosterone/renin ratio and non-suppressed aldosterone levels after saline infusion confirmed the diagnosis of primary hyperaldosteronism. Negative adrenal scintigraphic examination and a marked aldosterone response in the postural test supported the diagnosis of bilateral hyperplasia, despite the presence of left adrenal nodule in the CT-scan. Tetracosactide stimulation revealed a minor 21-hydroxilase defect and a marked ACTH-dependence of aldosterone secretion. Effective treatment with dexamethasone 1.0 mg every other night was maintained for 9 years, while in the meantime the left adrenal nodule apparently resolved and a right adrenal nodule become apparent. Finally worsening of blood pressure levels and increasing aldosterone concentrations with a positive scintigraphic labelling on the right adrenal gland led to right adrenalectomy that was so far curative. This case report demonstrates bilateral hyperplasia-adenoma evolution and suggests ACTH to be the relevant pathogenic stimulus, allowing for effective long-term treatment with dexamethasone.

Mild Adrenal Steroidogenic Defects and ACTH-Dependent Aldosterone Secretion in High Blood Pressure: Preliminary Evidence

“…This suggests that these patients also present a defective conversion of S to cortisol that is not more evident given the presence of the 21OHD [ 14 , 22 – 24 ]. Secondly, these patients also present an ACTH-dependent aldosterone response that so far has not been previously reported, except in single case reports [ 25 ]. Both the double block, involving the 11-hydroxylase enzyme besides the 21-hydroxylase enzyme, and the ACTH-dependent aldosterone response could explain the otherwise paradoxical association of the 21OHD with HBP.…”