Thyroid cancer is an unusual kind of cancer. The majority people who have it do incredibly well, because the cancer is typically found early and the treatments work well. After it is treated, thyroid cancer may come back, sometimes many years after treatment. Thyroid cancer develops as a consequence of the uncontrolled enlargement of irregular cells in the thyroid gland, resulting in a tumor. Several of these tumors are benign or non cancerous while several are malignant or cancerous.