Clinical characteristics and follow-up of incidentally found adrenal tumours - results from a single tertiary centre

To evaluate the clinical features, hormonal activity and natural evolution of adrenal incidentalomas (AI) in patients investigated in a single endocrinological centre and compare the prevalence of metabolic disorders and hypertension between subjects with AI and the general population. 515 patients with AI evaluated between 1995 and 2010 were retrospectively included in the study. Their anthropometric, clinical, metabolic and hormonal parameters were analyzed. Follow-up data was available for 142 patients. Mean age of all participants was 53.45 +/- 13.4 years (range 13-84) with strong female predominance - 376 (73%) vs. 139 (27%) males. Median size of AI was 28 mm (range 10-190 mm). Hormonal investigations revealed that 82.9% of patients harboured non-functioning adenomas, subclinical hypercortisolism was detected in 5.94%, overt Cushing's syndrome - in 2.7%, pheochromocytoma - in 1.9% and primary aldosteronism was diagnosed in 1% of patients. Adrenal carcinoma was identified in 1.7%. The prevalence of metabolic abnormalities and hypertension did not differ between patients with subclinical Cushing's syndrome and non-functioning adrenal adenomas. When compared to the general population, however hypertension, type 2 diabetes and metabolic syndrome were significantly more common in patients with hormonally inactive tumours. During the course of followup progression to overt hormonal hypersecretion was not observed. These results confirm other contemporary studies reporting lower rates of hormonally active and malignant lesions among AI as well as increased prevalence of hypertension and metabolic abnormalities in patients with non-functioning adrenal adenomas.