TERT and follicular thyroid adenoma: In addition, another study reported positive TERT promoter (C228T) mutations in four (5.3%) of 76 adenomas included in that study, but three of them were atypical follicular thyroid adenomas (AFTA) [26], which are now classified as follicular tumor of uncertain malignant potential by the World Health Organisation (WHO) 2017 guidelines [72].