There was no statistically significant difference between the IV type patients and the simple group in terms of operative time, postoperative hospital stay, postoperative complications, lesion location, lesion diameter, extrathyroidal invasion, thyroiditis, central lymph node dissection, central lymph node metastasis, lateral cervical lymph node dissection, lateral cervical lymph node metastasis, T stage, N stage, M stage and Ki67 (P > 0.05), see Table 6. Here, MKI67 is linked to thyroiditis.