TPO and autoimmune thyroid disease: The typical patient with hypothyroidism secondary to autoimmune thyroiditis will have an elevated TSH, a low FT4, and positive anti-TPO antibodies; however, in early stages of the disease, TSH may be normal and anti-TPO antibodies may be positive with or without goiter [11]; similarly, in present study, 5 cases showed increased anti-TPO without lymphoid infiltrate and normal TSH level.