This low power microscopic view of thyroid gland shows an early stage of Hashimoto thyroiditis with prominent lymphoid follicles containing large, active germinal centers. In this autoimmune disease, antithyroglobulin and antimicrosomal (thyroid peroxidase) autoantibodies can often be detected in serum. Other autoimmune diseases such as Addison 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 so that hyperthyroidism is usually not the most prominent features.