KRAS mutation and MIR (miRNA classifier)-positive. (A,D,E) Cytology preparations showed mostly microfollicular architecture and rare macrofollicles with Hürthloid features (cytology diagnosis of follicular lesion of undetermined significance with Hürthloid features) ([A] Diff-Quik, ×400; [D] Diff-Quik, ×200; [E] ThinPrep, ×400). (B,C) A histologic evaluation showed follicular adenoma ([B] H & E, ×100; [C] H & E, ×400).