TY - CHAP M1 - Book, Section TI - Chapter 2. Goiter A1 - Mekel, Michal A1 - Hodin, Richard A. A2 - Morita, Shane Y. A2 - Dackiw, Alan P. B. A2 - Zeiger, Martha A. PY - 2010 T2 - McGraw-Hill Manual: Endocrine Surgery AB - Goiter is defined as enlargement of the thyroid gland. It generally results from focal follicular cell hyperplasia at one or multiple sites within the thyroid gland, and it usually develops over years. Endemic goiter refers to enlargement of the thyroid gland secondary to iodine deficiency affecting more than 10% of the population in a defined geographic area. Sporadic goiter develops in subjects living in iodine-sufficient areas. Goiter encompasses a spectrum of entities, including diffuse, uninodular, or multinodular enlargement of the thyroid gland. The overall hormonal status of the thyroid nodules within the goiter determines the function of the gland and the definition. When enlargement of the thyroid gland is present without clinical or laboratory evidence of thyroid dysfunction, it is euthyroid multinodular goiter (MNG); when accompanied by hyperthyroidism, it is toxic nodular goiter (TNG). Less frequently, thyroid enlargement is caused by two other disorders such as fibrous chronic Hashimoto's thyroiditis, Graves' disease, or neoplasia. Retrosternal or substernal goiter refers to goiter that is associated with extension into the mediastinum. SN - PB - The McGraw-Hill Companies CY - New York, NY Y2 - 2024/04/16 UR - accesssurgery.mhmedical.com/content.aspx?aid=6162090 ER -