Adrenal incidentaloma.

Adrenal incidentalomas are incidentally discovered adrenal masses greater than 1 cm in diameter that appear to be clinically nonfunctioning. They are detected during imaging procedures of the abdomen and chest (CT, MRI, and ultrasonography) for an unrelated condition or symptom complex. With the widespread escalation in the use of these imaging modalities and marked improvements in image resolution, the probability of finding an incidentaloma on cross-section imaging is rapidly approaching the 6% prevalence of previously reported autopsy studies. All incidentalomas greater than 1 cm should be evaluated for hormonal activity, including a 1-mg overnight dexamethasone suppression test, total 24-hour urinary metanephrines and fractionated catecholamines, and, in the hypertensive patient, a serum potassium level and plasma aldosterone concentration to plasma renin activity ratio. All hormonally active tumors should be removed. Hormonally inactive tumors are resected based on size, imaging phenotype, and interval growth. Percutaneous biopsies are generally unwarranted and are potentially dangerous. Laparoscopic adrenalectomy has become the surgical procedure of choice for most benign functioning and nonfunctioning tumors of the adrenal gland. Subclinical metabolic abnormalities associated with adrenal incidentalomas remain an area of intense clinical research.