The clinical course of patients with adrenal incidentaloma: is it time to reconsider the current recommendations?

Abstract

Objective: The current guidelines for the management of adrenal incidentaloma advise hormonal and radiological follow-up of patients for 2-5 years after the initial diagnosis. However, the vast majority of adrenal incidentaloma are non-functional benign cortical adenomas that require no treatment, so the routine application of the current strategies often results in a number of unnecessary biochemical and radiological investigations. The aim of this study was to analyse the clinical course of patients with adrenal incidentaloma and to provide a critical review of the current management strategy of the disease.

Design and methods: This was a retrospective study performed in the Croatian Referral Center for adrenal gland disorders. The study included 319 consecutive patients with adrenal incidentaloma, 174 of which were followed for at least 24 months.

Results: The vast majority of patients were diagnosed with benign adrenal masses, whereas in about 5% of them adrenal tumor corresponded to adrenal carcinoma or metastasis. Tumor density was found to be superior to tumor size in distinguishing benign adrenal masses from malignant tumors and pheochromocytomas. During the follow-up, no patient demonstrated a clinically significant increase in tumor size. In addition, no changes, either in metanephrines and normetanephrines or in the activity of renin-aldosterone axis, were observed during the follow-up. Six patients developed subclinical Cushing's syndrome (SCS) whereas eight patients with SCS showed biochemical remission during follow-up.

Conclusion: The study suggests that the risk of an adrenal mass initially diagnosed as benign and non-functional becoming malignant or hormonally active is extremely low. Therefore, the clinical management of those patients should be tailored on an individual basis in order to avoid unnecessary procedures.