After radical surgical treatment of malignant tumors, there is a possibility of recurrence. The most common ones are papillary thyroid cancer and follicular thyroid cancer, which generally have a low recurrence rate if excised cleanly. In case of medullary carcinoma or undifferentiated carcinoma, the incidence of both types of cancer is not high, but the recurrence rate is very high, so different thyroid cancers have different incidence rates. Although it may be papillary carcinoma, it is late detection is advanced stage and may recur after surgery. Therefore, the reasons affecting recurrence are the early or late detection of thyroid cancer, thyroid cancer staging, and whether the malignancy is high or low; the higher the malignancy, the higher the possibility of recurrence.