Most adrenal incidentalomas do not require routine follow-up

Background Increased used of computerized tomography (CT) imaging has led to an increased number of incidentally found adrenal masses. Guidelines for management of adrenal incidentalomas have been extensive and inconsistent.

Methods We examined the biochemical characteristics and unenhanced density of adrenal incidentalomas in the Northern Ostrobothnia Hospital District in 2003–2013.

Results In this retrospective study, 451 adult patients with incidentally found adrenal tumours were identified. Of these tumours, 352 (78.0%) were adenomas, 10 (2.2%) phaeochromocytomas, 5 (1.1%) cortical carcinomas and 6 (1.3%) metastases. In the group of low attenuation (< 20 Hounsfield units, HU), none of the patients had a primary adrenal malignancy. The attenuation value was > 25 HU in all phaeochromocytomas. If the adrenal tumour was classified as an adenoma in the initial imaging, no growth or malignant transformation was observed if the patient did not have an earlier history of malignancy.

Conclusion Our results are consistent with the European Society of Endocrinology Clinical Practice Guideline. When a small (≤ 4 cm), hormonally inactive adrenal incidentaloma with an unenhanced attenuation ≤ 10 HU is found, further routine follow-up is not needed.

Minna Koivikko, Tuukka Itkonen, Juho Jaakola, Eija Pääkkö, Pasi Salmela, Tapani Ebeling

Minna Koivikko

M.D., Ph.D.

University of Oulu and Oulu University Hospital