Table II.

Screening Tests to Assess Hormonal Function of an Adrenal Mass

Pheochromocytoma	Primary Hyperaldosteronism	Cushing's Syndrome
(1) 24‐hour urine fractionated metanephrines + catecholamines or (2) plasma‐free metanephrines.	Morning aldosterone/plasma renin activity ratio ≥20 when absolute aldosterone ≥15 ng/dL with potassium ≥3.5 µg/L. Studies can be performed on all drugs except spironolactone, eplerenone, or amiloride.	(1) Dexamethasone suppression test: 1 mg dexamethasone between 11 pm and midnight; 8 am cortisol level should be <2.5 µg/dL or (2) 24‐hour urine‐free cortisol level, 4–50 µg/24 h.