Hashimoto’s disease /hä′shimō″tōz/ [Hakaru Hashimoto, Japanese surgeon, 1881–1934] , a progressive autoimmune thyroid disorder, characterized by the production of antibodies in response to thyroid antigens and the replacement of normal thyroid structures with lymphocytes and lymphoid germinal centers. The disease shows a marked hereditary pattern, but it is 20 times more common in women than in men. It occurs most frequently between 30 and 50 years of age but may arise in young children. The thyroid, typically enlarged, pale yellow, and lumpy on the surface, shows dense lymphocytic infiltration and follicular hyperplasia. The goiter is usually asymptomatic, but occasionally patients have difficulty swallowing and a feeling of local pressure. The thymus is usually enlarged, and regional lymph nodes often show hyperplasia. A definitive diagnosis can be made if a fluorescent scan shows a decrease or absence of thyroid-stable iodine and if the result of a hemagglutination test for thyroid antigens is positive. Replacement therapy with thyroid hormone is indicated for patients with thyroid deficiency and can prevent further enlargement of the goiter. Also called Hashimoto’s struma, Hashimoto’s thyroiditis, lymphocytic thyroiditis, struma lymphomatosa.
