Here is a low power microscopic view of a thyroid with Hashimoto's thyroiditis. Note the lymphoid follicle at the right center. This is an autoimmune disease and often antithyroglobulin and antimicrosomal (thyroid peroxidase) antibodies can be detected. Other autoimmune diseases such as Addison's disease or pernicious anemia may also be present. Both thyroid growth immunoglobulins (TGI) and thyroid stimulating immunoglobulins (TSI) are present, though blocking antibodies to TSI mitigate their effect.