<unk>  or chronic lymphocytic thyroiditis is an autoimmune disease where the body's own antibodies attack the cells of the thyroid.<unk>  was first described by<unk>  Hakaru in 1912. He named it struma lymphomatosa which was renamed as<unk>  in 1931.<unk>  can be classified as primary or secondary types. Rarely,<unk>  can be categorized under the polyglandular syndromes.<unk>  <unk>  is characterized by lymphocytic infiltration of the thyroid gland and production of antibodies that recognize thyroid-specific antigens. The pathogenesis is not yet completely understood. Thyroid cells undergo atrophy or transform into a type of follicular cell rich in mitochondria called Hurthle cell. It is currently thought that the disease is caused by abnormalities in cellular and humoral immunity which results in a localized cell-mediated immune response directed toward the thyroid parenchymal cells. This results in the decreased production of thyroid hormones.<unk>  is particularly common in middle aged women, Asians, and Whites.<unk>  usually begins slowly and may progress to hypothyroidism. Complications include heart failure, lymphoma, myxedema, and cervical compression. A positive history of autoimmune diseases and certain drug use are suggestive of<unk> . The most common symptoms of<unk>  include fatigue, constipation, and cold intolerance. Laboratory findings consistent with the diagnosis of<unk>  usually include increased thyroid stimulating hormone, decreased free T3 and free T4, and anti-thyroid peroxidase antibodies. Ultrasound findings associated with<unk>  are reduced echogenicity, glandular irregularities, and nodules. 24-hour iodine-123 uptake is decreased in<unk> . The mainstay of therapy for<unk>  is synthetic levothyroxine. Corticosteroids and selenium can also be used in certain cases. Thyroidectomy is usually performed when the enlarged thyroid produces cervical compression symptoms and there is a high suspicion for malignancy.
Hashimoto's thyroiditis
De Quervain's thyroiditis
Riedel's thyroiditis
Silent thyroiditis
Graves' disease
Primary thyroid lymphoma
Medullary thyroid cancer
Nodular thyroid disease