Poorly Differentiated Carcinoma Yuri E. Nikiforov DEFINITION Poorly differentiated thyroid carcinoma is an aggressive malignant tumor of follicular cell origin that is characterized by a partial loss of thyroid differentiation…

Diffuse and Nodular Hyperplasia Paul W. Biddinger GRAVES DISEASE (DIFFUSE TOXIC HYPERPLASIA) Definition Graves disease, also known as diffuse toxic hyperplasia or diffuse toxic goiter, is an autoimmune disorder characterized…

Thyroiditis Paul W. Biddinger Thyroiditis encompasses a heterogeneous group of inflammatory diseases of the thyroid. The study of these inflammatory conditions can be challenging because of the different approaches to…

Hyalinizing Trabecular Tumor Yuri E. Nikiforov DEFINITION Hyalinizing trabecular tumor is a rare noninvasive follicular cellderived thyroid neoplasm with a characteristic trabecular growth pattern and intratrabecular hyalinization. The malignant potential…

Other Nonneoplastic Disorders Paul W. Biddinger AMIODARONE-INDUCED THYROID DISEASE Amiodarone is an iodinated drug used for the treatment of cardiac arrhythmias. Although an effective drug for arrhythmias, amiodarone can produce…

Embryology and Developmental Lesions Paul W. Biddinger EMBRYOLOGY Embryologic Origination Knowledge of the embryologic development of the thyroid is key to understanding several abnormalities of the thyroid gland. The gland…

Thyroid Tumors: Classification, Staging, and General Considerations Yuri E. Nikiforov CLASSIFICATION A histologic classification of thyroid tumors is shown in Table 7.1. It incorporates main principles of the current World…

Normal Anatomy and Histology Paul W. Biddinger Descriptions of the thyroid and related diseases date back to antiquity. The thyroid was identified by European anatomists during the Renaissance including Vesalius…

Thyroid Physiology Peter Kopp THYROID HORMONE SYNTHESIS AND SECRETION Thyroid hormones are essential for normal growth and development, particularly of the central nervous system, and they play a key role…