Diffuse nontoxic goiter Pathogenesis Dietary iodine deficiency -endemic Not apparent - sporadic Impaired synthesis of thyroid hormone Rise tsh level in serum Hypertrophy and hyperplasia of thyroid follicular cells Gross enlargement of the thyroid glandDiffuse nontoxic goiter Pathogenesis: Dietary iodine deficiency endemic Not apparent sporadic Impaired synthesis of thyroid hormone Rise TSH level in serum Hypertrophy and hyperplasia of thyroid follicular cells Gross enlargement of the thyroid gland