Thyroid gland neoplasms

Thyroid neoplasms are common and affect many individuals. This chapter outlines the development of the thyroid gland, the physiological function of its hormones, pathogenesis, diagnosis, and treatment of tumoral or neoplastic thyroid diseases. We describe the currently understood pathogenesis and the diagnosis of thyroid neoplasms based on the integration of clinical features with pathologic findings, including cytopathology diagnosis using fine needle aspiration, tissue biopsy, or surgical resection of a thyroid mass. The evolution of the pathologic classification and cytologic criteria for diagnosing thyroid neoplasms are described and integrated with molecular genetic abnormalities identified in the last decade underlying "sporadic" thyroid epithelial neoplasms. Importantly, hereditary syndromes associated with thyroid diseases are increasingly recognized, including syndromic and non-syndromic forms of thyroid tumors. Awareness is essential to recognize the familial nature of these cancers. We describe features that would help clinicians and pathologists to identify familial cancers. The molecular genetic features underlying each specific diagnosis are discussed, including their clinical significance in prognosis and treatment. Finally, the role of emerging technologies in enhancing the diagnosis and clinical management of thyroid neoplasms is discussed. This chapter intends to encourage a knowledge network connecting multi-disciplinary healthcare providers to advance the care of patients with thyroid neoplasms.