TY - CHAP M1 - Book, Section TI - Thyroid Nodular Disease and Thyroid Cancer A1 - Jameson, J. Larry A1 - Mandel, Susan J. A1 - Weetman, Anthony P. A2 - Jameson, J. Larry A2 - Fauci, Anthony S. A2 - Kasper, Dennis L. A2 - Hauser, Stephen L. A2 - Longo, Dan L. A2 - Loscalzo, Joseph Y1 - 2018 N1 - T2 - Harrison's Principles of Internal Medicine, 20e AB - Goiter refers to an enlarged thyroid gland. Biosynthetic defects, iodine deficiency, autoimmune disease, and nodular diseases can each lead to goiter, although by different mechanisms. Biosynthetic defects and iodine deficiency are associated with reduced efficiency of thyroid hormone synthesis, leading to increased thyroid-stimulating hormone (TSH), which stimulates thyroid growth as a compensatory mechanism to overcome the block in hormone synthesis. Graves’ disease and Hashimoto’s thyroiditis are also associated with goiter. In Graves’ disease, the goiter results mainly from the TSH-R–mediated effects of thyroid-stimulating immunoglobulins. The goitrous form of Hashimoto’s thyroiditis occurs because of acquired defects in hormone synthesis, leading to elevated levels of TSH and its consequent growth effects. Lymphocytic infiltration and immune system–induced growth factors also contribute to thyroid enlargement in Hashimoto’s thyroiditis. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/28 UR - accessmedicine.mhmedical.com/content.aspx?aid=1176624953 ER -