Tumorous Growths in the Pituitary and Trachea Following Radio toxic Dosages of I 131 . ∗

Abstract

Summary

Following doses of radioactive iodine sufficient to cause destruction of most or all of the thyroid, tumorous enlargements were found in the pituitary glands and tracheas of mice. Hypophyseal growths as large as 240 milligrams (control, 2.1 mg) were found. Less than 10%percnt; of animals sacrificed more than 250 days after I¹³¹ administration had pituitaries smaller than 10 mg in weight.

Tracheal tumors of the fibrous tunica propria, obstructing the tracheal lumen, were of lower incidence (4%percnt;) but appeared earlier. Fibrous thickenings of the tunica propria, and metaplastic regeneration of tracheal epithelium were more common.