For this investigation, we focused on analyzing the frequency of the ARMC5 allelic variants in a multicenter cohort of patients with adrenal incidentalomas (bilateral and unilateral adrenal nodules) or with bilateral adrenal nodules associated with adrenal ACTH pituitary independent Cushing's syndrome. The gene discussed is ARMC5; the disease is Cushing syndrome due to macronodular adrenal hyperplasia.