Are small adrenal incidentalomas solely a radiological finding?

Objective: The criterium defining the threshold size of adrenal incidentaloma (AI) is a size greater than 1cm diameter. However, data concerning AI1cm in diameter is scant. The aim of this study was to evaluate the function of adrenal masses1cm and to compare them with adrenal masses>1cm. Materials and Methods: The study included 130 consecutive patients with AI (38 and 92 AI at 1cm and >1cm, respectively). The patients were evaluated according to demographic and hormonal characteristics. Results: The prevalence of SCS was 5.3 and 12% in AI1cm and >1cm diameter, respectively. Hyperaldosteronism was found only in patients with >1cm AI. Pheochromocytoma were not found in either group. Patients with >1cm AI had a higher prevalence of SCS and primary hyperaldosteronism than patients with 1cm AI, but the difference was not significant. The prevalence of diabetes and hypertension was high both in non-functional AI with 1cm and >1cm patients and showed no significant difference between the 2 groups. Conclusion: Our study is the first to focus on the clinical and hormonal characteristics of patients with 1cm AI. Those with AI1cm harboured SCS, as was the case for AI>1cm. Similar to AI>1cm, non-functional AI1cm also had a higher prevalence of diabetes and hypertension.