An adrenal incidentaloma is a mass lesion greater than 1 cm in diameter, serendipitously discovered by radiologic examination . This entity is the result of technological advances in imaging such as computed tomography (CT) and magnetic resonance imaging (MRI). Discovery of an adrenal mass raises two questions that determine the degree of evaluation and the need for therapy :
●Is it malignant?
●Is it functioning?
The approach to the evaluation and management of adrenal incidentalomas is reviewed here. Detailed discussions of adrenal carcinoma and functioning adrenal tumors such as pheochromocytomas and aldosteronomas are found elsewhere. (See "Clinical presentation and evaluation of adrenocortical tumors" and "Clinical presentation and diagnosis of pheochromocytoma" and "Clinical features of primary aldosteronism".)
Adrenal masses may be found incidentally when CT scans or MRIs are done for other reasons. In a study of 61,054 abdominal CT scans performed from 1985 to 1990, an incidental adrenal tumor (incidentaloma >1 cm) was detected in 259 patients (0.4 percent of all CT scans) . A subsequent study, utilizing higher resolution scanners, reported a prevalence of adrenal incidentaloma on abdominal CT of 4.4 percent . The prevalence of adrenal incidentaloma is higher in older patients (10 percent) .