The presence of enlarged lymph nodes after thyroid cancer surgery does not in most cases indicate recurrence or metastasis of the tumor. This is because the current clinical types of thyroid cancer usually include follicular carcinoma, papillary carcinoma, and medullary and undifferentiated carcinoma. The first three pathological types of thyroid cancer can be cured by timely radical surgery and lymph node dissection in the neck according to current clinical statistics. The swelling of lymph nodes in the neck one year after surgery is usually due to the lymphatic tracts ligated during the local lymph node dissection and the subsequent obstruction of lymphatic flow. Therefore, swollen lymph nodes in the neck one year after thyroid cancer surgery are usually caused by lymphatic flow obstruction and do not represent recurrence or metastasis of the tumor.