Thyroid cancer is a disease characterized by the uncontrolled growth of cells in the thyroid gland. It generally has a good prognosis, with a very high treatment success rate. It can manifest with symptoms such as swelling in the neck, a palpable mass, or a thyroid nodule. Once diagnosed, the primary treatment method is usually surgery. Following surgery, additional treatments such as radioactive iodine therapy and, in some cases, external radiation therapy may be applied depending on the situation.