Pituitary enlargement followed by regression with thyroid hormones on computed tomtgraphic scanning in patients with primary hypothyroidism

Pituitary enlargement was detected on CT scanning in 10 of 17 patients with primary ypothyroidism before thyroid hormone replacement therapy was given. The height of pituitary land on CT scanning was inversely related with the patients’ age （r=-0.7837, P＜0.01）. The erum rolactin levels were slightly elevated in patients with pituitary enlargement. After eplacement therapy with thyroid tablet the enlarged pituitary glands returned to normal size n f seven patie- nts when they were in euthyroid state, while another patient’s pituitary was till enlarged following inadequate dose of thyroid tablet. In conclusion, pituitary nlargement as frequently seen in patients with primary hypothyroidism and could return to normal after ffective treatment with thyroid hormones.