Incidental asymptomatic adrenal masses detected by computed tomographic scanning. Is operation required?

Until recently, adrenal masses came to clinical attention either from local symptoms due to massive enlargement or from manifestations of excess hormones production. During the last year, an adrenal mass was identified as an incidental finding in nine patients undergoing abdominal computed tomographic (CT) scanning for unrelated problems. These five men and four women ranged in age from 41 to 73 years. Eight were hypertensive. After the CT scan, each was evaluated for catecholamine or steroid hypersecretion. Only one had clearly elevated urinary vanillylmandelic acid, metanephrine, and catecholamine levels. Equivocal evidence of catecholamine excess was seen in five patients who had slight elevation of one urinary metabolite or of plasma epinephrine or norepinephrine levels. Three patients had no evidence of medullary or cortical hyperfunction on repeated testing. Eight patients were good operative risks and underwent unilateral adrenalectomy without complication. Masses ranging in size from 1 to 4 cm were found in each. These included four cortical adenomas, two adrenal cysts, one adrenal lipoma, and one pheochromocytoma. The pheochromocytoma occurred in the patient with strong biochemical evidence of disease. With wider application of CT imaging, increasing numbers of asymptomatic adrenal masses will be detected. Care in interpreting the clinical significance of these masses and caution in recommending treatment are required.