Hashimoto Thyroiditis

Introduction

-Hashimoto thyroiditis is a common chronic autoimmune inflammatory disease 

-It is the most common  thyroid disorder in the United States

-it is the most common cause of hypothyroidism 

-it is caused by an autoimmune attack on the thyroid

-it is associated with a host of other autoimmune diseases 

-Autoantibodies in Hashimoto thyroiditis are  thyroglobulin antibody (Tg Ab), thyroidal peroxidase antibody (TPO Ab) and the TSH receptor–blocking antibody (TSH-R [block] Ab). 

-It shows female preponderance and is predominantly a disease of middle age 

-It is characterized by destruction of thyroid follicles and infiltration by lymphocytes and plasma cells interspersed by enlarged follicular epithelial oncocytic cells with abundant pink eosinophilic granular cytoplasm (Hürthle cells or Askanazy cells) 

-it is associated with an increased incidence of papillary carcinoma of the thyroid and primary thyroid lymphoma 

Symptoms & Signs 

-Diffusely enlarged, firm, rubbery, nontender and nodular thyroid which becomes smaller with the progression of the disease

-Some patients may develop hypothyroidism or rarely hyperthyroidism and exhibit their clinical manifestations 

Diagnosis 

Thyroid antibodies: Elevated antithyroglobulin and antithyroid peroxidase antibodies 

Laboratory findings vary based on thyroid status 

If patient is euthyroid: normal TSH and normal thyroid hormones 

if hypothyroid, elevated TSH and low thyroid hormones 

if hyperthyroid, suppressed TSH and elevated thyroid hormones 

FNAB: thyroid gland infiltrated by lymphocytes and Hürthle cells or Askanazy cells

Treatment 

Symptomatic/Cosmetic reasons: Surgery 

Hypothyroid status: Thyroid replacement therapy