The transformation of an adrenocortical adenoma (ACA) to an adrenocortical carcinoma (ACC) is extremely rare. Current guidelines suggest against further imaging studies and follow-up in patients with nonfunctional adrenal incidentalomas (NFAIs) with benign imaging characteristics. Herein, we present a 64-year-old male patient diagnosed initially with a NFAI of 3 cm in size with imaging characteristics consistent with an ACA. However, 13 years after initial diagnosis, this apparent ACA developed into a high-grade cortisol and androgen-secreting ACC with synchronous metastases. The literature review revealed a further 9 case reports of adrenal incidentalomas initially characterized as ACA that subsequently developed into ACC within a period ranging from 1 to 10 years. The pathogenesis of transformation of an initially denoted ACA to ACC is not fully delineated, although the existing literature focuses on the preexisting or changing genetic background of these lesions, highlighting the need to develop robust prognostic markers to identify patients at risk and individualize the follow-up of these unique cases.
Keywords: adrenal adenoma; adrenal incidentaloma; adrenal incidentalomas; adrenocortical carcinoma; malignant evolution; malignant transformation.
© The Author(s) 2024. Published by Oxford University Press on behalf of the Endocrine Society.