Additional Info: |
Hashimoto's Thyroiditis (HT) occurs predominantly in individuals over 40 years of age. HT has a higher incidence in FEMALES (female:male; 5:1). HT is the most common cause of thyroiditis in areas where iodine levels are sufficient (Goiter is more common in the context of iodine insufficiency). HT Presents as diffuse, firm thyroid enlargement. Initially patients may be mildly hyperthyroid, then later hypothyroid. Seen here is a lymphocytic infiltration with prominent follicles with germinal centers. Rare multinucleated giant cells may be present (marked granulomatous inflammation is more suggesting of Subacute granulomatous thyroiditis (DeQuervian's). Fibrosis can be seen and can be (is rarely) extensive. Excellent prognosis, except: Increased risk of lymphoma (extranodal marginal zone lymphoma). Pathogenesis may involve autoantibodies to Thyroglobulin, thyroid peroxidase, TSH receptor, Iodine transporter. HLA-DR5, HLA-DR3 which lead to antibody dependent cell mediated cytotoxicity.
|