MKI67 and thyroiditis: Compared with the plain group, type III and type IV had a lower proportion of nodal goitre (42.9% vs. 84.8%, P < 0.001), (50% vs. 84.8%, P=0.007), type III had a higher proportion of thyroiditis (28.6% vs. 8.7%, P=0.029), fewer central lymph node dissections [3(2,5) vs. 6(4,10), P=0.033], fewer central lymph node metastases [0(0,0) vs 3(2,6), P=0.005], fewer lateral neck lymph node metastases [0(0,0,5) vs 4,5(2.9), P=0.035], higher proportion of N0 stage (78.6% vs 42.4%, P=0.012), lower Ki67 score [1.0(1.0,1.0) vs 2.0(1.0,5.0), P=0.032].