Incidentally found adrenocortical carcinoma. A study of 21 patients.

The frequency of adrenocortical carcinoma was studied in a group of 311 incidentally discovered adrenal tumours. Clinical characteristics were also analysed. Ultrasound scan and computed tomography were the main imaging techniques used. Hormonal examinations were also carried out. The patients with an adrenal tumour diameter greater than or equal to 4.0 cm, and those with excess steroid production were recommended for surgery. Of 131 patients treated with surgery, adrenocortical carcinoma was diagnosed in 21 cases. The diameter of these tumours ranged between 3.2 and 20.0 cm. The majority of these were hormonally inactive, but, in some cases increased corticosteroid secretion was noted. In 17/21 patients, mitotane was administered following surgery, with a good response in 13 cases. These 21 cases were compared with a group of 51 patients with clinically overt adrenocortical carcinoma.