Because of its relative rarity and favorable outcome, it has not been feasible to assess medical interventions for thyroid cancer using randomized prospective trials. The approach to diagnosis and treatment relies to a great extent on information derived from retrospective studies. Overall prognosis and survival rates have been edging upward over the past two decades. This is attributed to a wider acceptance of total thyroidectomy as the primary surgical strategy. The appropriate indication of radioiodine therapy remains controversial, and physicians must be familiar with staging criteria to make educated decisions. We are now beginning to understand the genetic mechanisms of thyroid tumor initiation and progression. There are still major challenges ahead. Thyroid Cancer provides comprehensive updates on the epidemiology, pathogenesis, diagnosis and treatment of thyroid neoplasms. Although the material should be of particular interest to scholars in the field, the contributors have striven to make it of practical use to physicians who treat patients with thyroid disease.