Inclusion Criteria:  unilateral adrenal incidentaloma larger than 1 cm cortisol after 1-mg overnight dexamethasone suppression test (1mgDST) between 1.8 and 5 mcg/dl  Exclusion Criteria:  hypogonadism, thyrotoxicosis, chronic renal failure and hepatic disease, alcoholism, eating, rheumatologic or hematological disorders; intake of drugs influencing cortisol and dexamethasone metabolism or cortisol secretion; signs of hypercortisolism (moon facies, striae rubrae, easy bruising); possible metastatic disease or radiologic features not consistent with adrenocortical adenoma at computed tomography (CT); pheochromocytoma and aldosteronoma; non-adrenal SH.