Preclinical Cushing's syndrome due to adrenocorticotropin-independent bilateral adrenocortical macronodular hyperplasia with concurrent excess of gluco- and mineralocorticoids

A 48-year-old man with bilateral adrenal incidentalomas was studied. Although the serum cortisol level eras normal, autonomous cortisol secretion was shown by the loss of diurnal rhythm, no suppressibility by dexamethasone, and compere suppression of plasma adrenocorticotropin levels, Imaging analyses revealed bilateral adrenal masses, showing isotope uptake. He was diagnosed as preclinical Cushing's syndrome dire to adrenocorticotropin-independent bilateral adrenocortical macronodular hyperplasia, confirmed histologically. Despite the undetectable plasma adrenocorticotropin level and renin activity, serum mineralocorticoids levels were not suppressed, which were decreased after subtotal adrenalectomy. It was suggested that hyperplastic adrenal glands could produce both gluco-and mineralocorticoids concomitantly.