Incidentally discovered adrenal mass (incidentaloma): investigation and management of 208 patients

Incidentally discovered adrenal masses are fairly common, although there are some controversies concerning the results of hormonal investigation (especially DHEAS values) and the methods of management. We summarize our experience in diagnosis, pathological findings and treatment of a large group of patients with incidentally found adrenal tumours.

Our study included patients referred to the Department of Endocrinology of the Centre of Post-graduate Medical Education (Warsaw, Poland) during the last 10 years because of an adrenal tumour incidentally found on ultrasound scan. In all cases this was confirmed by computed tomography. There were 208 patients (148 female and 60 male), 14-76 years old. Unilateral adrenal masses were found in 172 patients (right 106, left 66), while bilateral masses were demonstrated in 36 patients. The size of the tumours ranged between 0.8 and 21.0 cm. The most common clinical abnormalities were hypertension (36 cases), obesity (23 cases), diabetes (8 cases), Addison's disease (6 cases).

Endocrine tests evaluating pituitary-adrenal function (urinary excretion of 17-hydroxycorticosteroids, 17-ketosteroids and catecholamines, plasma concentrations of ACTH, cortisol, DHEAS, androstendione and testosterone, dexamethasone suppression test and corticotrophin-releasing hormone stimulation test).

Cortisol hypersecretion was noted in two patients with coexisting Cushing's disease and high normal 17-OHCS values with lack of dexamethasone suppressibility were found in six other patients with pre-clinical Cushing's syndrome. More common were subtle hormonal abnormalities: low ACTH levels (in 33 out of 98 investigated patients), diminished dexamethasone suppressibility and lack of ACTH response in the CRH test (in two out of 12 patients). Urinary catecholamine excretion was elevated in nine patients. In the group of 85 patients treated by surgery the most frequent pathological findings were: adrenocortical adenoma (21), carcinoma (17), phaeochromocytoma (13), metastatic masses (12) and myelolipoma (10). The size of carcinomas ranged from 3.2 to 20.0 cm, while the size of non-malignant tumours ranged from 1.5 to 21.0 cm.

Every patient with an incidentally discovered adrenal mass has to be investigated to detect malignancy and subtle hormonal overproduction, to select the cases for surgical treatment. Most of the adrenocortical carcinomas were > 7.0 cm in diameter. For prophylactic purposes, adrenal incidentalomas > 4.0 cm should be treated by surgery, while the smaller ones could be followed-up (with special care for those between 3.0 and 4.0 cm).