Subtle glucocorticoid excess in patients with adrenal incidentaloma

Incidentally discovered adrenal tumors (incidentalomas) are fairly common since the advent of noninvasive methods of imaging the abdomen. Patients with incidentaloma usually undergo screening for overproduction of glucocorticoids by measurement of basal steroid excretion. We describe an asymptomatic patient with an incidentaloma with normal basal steroid excretion whose only manifestation of subtle steroid overproduction was the failure of steroid excretion to be suppressed normally with dexamethasone. It appears that the more careful the search for subtle evidence of steroid overproduction in patients with incidentaloma, the more common the finding; perhaps up to 50% of patients with incidentaloma have some subtle steroid overproduction. We review the literature on this subject, and evaluate the various possible approaches of how intensively to study steroid dynamics in patients with incidentaloma.