Endocrine Abstracts

Adrenal incidentalomas are increasingly recognized today as a result of technology use, such as computed tomography and magnetic resonance imaging. Adrenal incidentalomas are of diverse nature and their secretory activity is currently on research focus.

The aim was to describe 39 consecutive patients with adrenal incidentalomas presenting over a period of 1 year.

Materials and methods: A group of 39 consecutive patients with adrenal incidentalomas are described. All patients were investigated for hormonal activity of the incidentalomas. Morning and evening cortisol, urine free cortisol, aldosterone and renin in supine and upright position, catecholamines, metanephrines and urine VMA were measured. A low dose dexamethasone suppression test was performed in all patients. The imaging characteristics of the incidentalomas were fully characterized on computed tomography and magnetic resonance imaging. In the case where surgery was decided the histology of the removed adrenal tumor was noted.

Results: Within the group of 39 consecutive patients with adrenal incidentalomas 14 (36%) had abnormal suppression of morning cortisol after the low dose dexamethasone suppression test, although morning and evening cortisol were normal and the cortisol diurnal rhythm was normal. Within the group of 39 cases of adrenal incidentalomas two patients had clearly abnormal ratio of aldosterone to plasma renin activity and were found to have primary hyperaldosteronism and seven (17.9%) patients had a ratio of aldosterone to plasma renin activity of 20–50, suggestive of aldosterone hypersecretion. A patient had a pheochromocytoma and another had a myelolipoma.

Conclusion: Adrenal incidentalomas represent a diverse group of adrenal pathology. Many appear to have low grade secretory activity which may not be enough to cause the appearance of the respective clinical picture in the patient, remaining thus subclinical. The natural history, pathology and secretory activity of adrenal incidentalomas is a subject of extreme interest and needs further investigation.