Experience gained from operation of 103 adrenal incidentalomas

Adrenal incidentaloma poses a perplexing problem for physicians. The challenge is to identify the rare functioning or malignant adrenal tumor that should be removed.

From 1970 until December 1996, we managed 579 patients with adrenal hyperplasia or neoplasm. Of these, 110 were followed without any operation and 469 were operated on. The histology from the operated patients revealed 145 pheochromocytomas, 72 Cushing's syndrome, 98 aldosteronomas, 21 virilizing tumors, 3 feminizing tumors, 98 non-functioning adrenalomas, 17 metastases, 7 cysts, and 15 miscellaneous tumors.

Among the 98 non-functioning adrenal tumors, 79 were incidentalomas. Histological examination of 103 operated incidentalomas found 55 adenomas (5 functioning=aldosteronomas), 12 benign pheochromocytomas, 3 malignant or suspicious pheochromocytomas, 8 cystic lymphangiomas, 4 metastases, 4 angiomas, 3 ganglioneuromas, 4 myelolipomas, 1 hyperplasia, 2 hematomas, 2 cysts, and 5 adreno-cortical carcinomas. Among the non-operated incidentalomas, the most frequent findings were adenomas, metastases, hematomas, cysts and pseudotumoral hyperplasia; three disappeared spontaneously. No patients died of unrecognized adrenocortical carcinoma.

Our experience confirms that in case of incidentaloma, the first concern is a nonfunctional pheochromocytoma (15%), and the less common occurrence is adreno-cortical carcinoma (2%). We recommend a restrictive surgical approach in the setting of adrenal incidentalomas.