The chance of metastasis of thyroid cancer is actually relatively small, especially papillary cancer which has the best prognosis and accounts for the highest proportion of thyroid cancer and is not prone to recurrence and metastasis. However, undifferentiated carcinoma can easily invade the surrounding tissues and progress faster, so it is easy to metastasize and recur. There was a case of papillary thyroid carcinoma in which the whole neck grew again in less than 2 months after cutting it clean. Papillary thyroid cancer is not easy to recur and metastasize, but it may recur and metastasize, but it is less likely, so it is also very important to review thyroid cancer regularly after surgery.