Hashimoto's thyroiditis is characterized clinically as a commonly occurring, painless, diffuse enlargement of the thyroid gland occurring predominantly in middle-aged women. The patients are often euthyroid, but hypothyroidism may develop. The thyroid parenchyma is diffusely replaced by a lymphocytic infiltrate and fibrotic reaction; frequently, lymphoid germinal follicles are visible. Persons with Hashimoto's thyroiditis have serum antibodies reacting with TG, TPO, and against an unidentified protein present in colloid. In addition, many patients have cell mediated immunity directed against thyroid antigens, demonstrable by several techniques. The incidence is on the order of three to six cases per 10,000 population per year, and prevalence among women is at least 2%. The gland involved by thyroiditis tends to lose its ability to store iodine, produces and secretes iodoproteins that circulate in plasma, and is inefficient in making hormone. Thus, the thyroid gland is under increased TSH stimulation, fails to respond to exogenous TSH, and has a rapid turnover of thyroidal iodine.
Diagnosis is made by the finding of a diffuse, smooth, firm goiter in a young woman, with strongly positive titers of TG Ab and/or TPO Ab and a euthyroid or hypothyroid metabolic status. A patient with a small goiter and euthyroidism does not require therapy unless the TSH level is elevated. The presence of a large gland, progressive growth of the goiter, or hypothyroidism indicates the need for replacement thyroid hormone. Surgery is rarely indicated. Development of lymphoma, though very unusual, must be considered if there is growth or pain in the involved gland.
Copyright © 2000-2024, MDText.com, Inc.