Fig. 1
Criteria for the diagnosis of poorly differentiated thyroid carcinoma. FTC: follicular thyroid carcinoma; PTC: papillary thyroid carcinoma; HPF: high power field; 50 random mitotic counts average per 10 HPF X400 in areas with solid/trabecular/insular (STI) growth pattern (Volante M., personal communication 2017). (Modified from Fig. 1 in Volante et al. 2007)