Malignant tumors of the thyroid gland are called thyroid cancer. When thyroid cancer is not characterized and not clearly diagnosed both can be called thyroid nodules. So the difference is that thyroid nodules cover a larger area, and both benign and malignant tumors of the thyroid gland can be called thyroid nodules in the early stages. For malignant tumors, they include papillary thyroid carcinoma, which is more common and more frequent, and medullary thyroid carcinoma and undifferentiated carcinoma, which are relatively rare. Papillary thyroid carcinoma has a good survival rate, a low recurrence rate in the distant postoperative period, and rarely affects the life expectancy of most patients after treatment. Medullary carcinoma and undifferentiated carcinoma, on the contrary, but their incidence is low and timely treatment after detection can also effectively avoid distant risks and complications. In terms of treatment, thyroid nodules that are benign and asymptomatic do not require prophylactic treatment. Malignant tumors of the thyroid, once detected, need to be treated as early as possible, regardless of whether they are symptomatic or not.