What are the serologies for an aldosterone (aldosterone) secreting tumor, specifically primary aldosteronism?

From the Guidelines

To diagnose an aldosterone-secreting tumor (primary aldosteronism), the recommended serologic testing begins with measuring the aldosterone-to-renin ratio (ARR), with an elevated ARR (typically >30 when PAC is in ng/dL and PRA in ng/mL/hr) suggesting primary aldosteronism, as supported by the most recent guidelines 1. The diagnosis of primary aldosteronism is crucial due to its significant impact on morbidity, mortality, and quality of life, with patients having a higher risk of cardiovascular events and target organ damage compared to those with primary hypertension. Key considerations in the diagnostic process include:

• Measuring plasma aldosterone concentration (PAC) and plasma renin activity (PRA) or direct renin concentration in the morning after the patient has been upright for at least 2 hours.
• Ensuring adequate sodium intake before testing to avoid false positives from sodium depletion.
• Adjusting or discontinuing medications that affect the renin-angiotensin-aldosterone system, such as diuretics, ACE inhibitors, ARBs, and beta-blockers, for at least 2-4 weeks before testing.
• Stopping mineralocorticoid receptor antagonists like spironolactone for at least 4-6 weeks before testing. If the initial screening is positive, confirmatory testing is needed, which may include oral sodium loading, saline infusion, fludrocortisone suppression, or captopril challenge tests, as recommended by recent guidelines 1. Additional laboratory findings often include hypokalemia, mild hypernatremia, and metabolic alkalosis, though normokalemic primary aldosteronism is increasingly recognized. The management of primary aldosteronism depends on its subtype, with unilateral forms being amenable to surgical treatment and bilateral forms requiring lifelong medical treatment with mineralocorticoid receptor antagonists (MRAs) such as spironolactone or eplerenone, as stated in the latest guidelines 1.

From the FDA Drug Label

The FDA drug label does not answer the question.

From the Research

Serologies for Aldosterone Secreting Tumor

• The diagnosis of primary aldosteronism (PA) involves determining the plasma aldosterone to renin ratio (ARR) as an initial screening test 2, 3, 4, 5.
• A raised ARR ratio suggests PA, and confirmatory suppression tests are then performed to confirm the diagnosis 2, 3, 4, 5.
• The differential diagnosis of hypokalemic hypertension with low renin includes mineralocorticoid excess, with the mineralocorticoid being cortisol or 11-deoxycorticosterone, apparent mineralocorticoid excess, pseudo-hypermineralocorticoidism in Liddle syndrome or exposure to glycyrrhizic acid 2.
• Adrenal computed tomography is performed for all patients to exclude adrenocortical carcinoma and to identify unilateral aldosterone hypersecretion 2, 3, 5.
• Adrenal vein sampling is performed to detect whether or not aldosterone hypersecretion is unilateral, and to establish treatment options 2, 3, 5.
• Patients with unilateral disease are most appropriately managed with adrenalectomy, which can cure aldosterone excess and hypokalemia, but not necessarily hypertension 2, 3, 5.
• Patients with bilateral adrenal disease and those believed not to be surgical candidates are managed with mineralocorticoid antagonists 3, 4, 5.
• The presence of an aldosterone- and cortisol-co-secreting adrenocortical tumor should be considered if a patient has PA and an adenoma that is larger than 2.5 cm, cortisol that is non-suppressible with overnight low-dose dexamethasone, or grossly elevated serum levels of hybrid steroids, such as 18-OH-F 6.