TG and neoplasm: IHC was performed using a panel of antibodies to tumor markers, which revealed follicular cells were positive staining for thyroid transcription factor‐1 (TTF‐1), thyroglobulin (Tg) (Figure 2E,F), cytokeratin (CK), CK8/18 and weakly positive for CK7, while negative for calcitonin, excluding medullary thyroid cancer.