Incidentally discovered adrenal tumors: an institutional perspective.

With the aim of developing guidelines for investigation and management of adrenal incidentalomas, 2066 patients with adrenal masses were analyzed from a total of 61,054 computerized tomographic (CT) scans done from 1985 through 1989. Excluding patients with previous or concurrent malignancies, adrenal tumors localized after biochemical documentation of disease, and adrenal nodules less than 1 cm, 259 patients (0.4%) remained for analysis. Added to these were 83 patients (total 342) in whom the adrenal tumor had been found elsewhere before referral. There were 136 men and 206 women with a mean age of 62 years. Tumor diameter ranged from 1 to 11 cm (average 2.5 cm). Studies to evaluate biochemical hyperfunction were performed in 172 patients (50%), 2 of whom were found to have cortisol-producing tumors and 5 pheochromocytomas. Histologic proof of diagnosis was obtained in 55 patients at the time of adrenalectomy. Malignancy was discovered in five patients (four primary and one metastatic), the smallest malignant tumor measuring 5 cm. In the 287 patients without histologic diagnoses, a minimum of 1 year of clinical follow-up was obtained in 251 (88%), including repeat CT scan in 156 (54%). None of these patients had clinical or biochemical adrenal abnormalities. We suggest (1) biochemical screening in patients with incidentalomas larger than 1 cm, (2) surgical excision of tumors 4 cm or greater, and (3) a comparison CT scan approximately 3 months after diagnosis in patients with tumors less than 4 cm in whom observation has been chosen.