Tumorous Growths in the Pituitary and Trachea Following Radio toxic Dosages of I131.

Abstract

Single subcut. injns. of carrier-free I131 were given to inbred strains of mice in dosages sufficient to destroy most or all of the thyroid gland (80 to 325 microcuries). Tumorous growths were found in the trachea after 4 mos., and in the hypophysis after 6 mos. Hypophyseal tumors formed from the anterior lobe and weighed as much as 242 mg. (control 2.1 mg.). Less than 10% of all I131-treated mice had pituitaries of less than 5 times the control wt., 200 days or longer after treatment. Most of these tumors displaced parts of the brain, produced blindness, and distorted the shape of the head by separating cranial bones. Tracheal tumors displaced parts of the brain, produced blindness, and distorted the shape of the head by separating cranial bones. Tracheal tumors were fibrous growths derived from the tunica propria. They were of 4% incidence and caused death by tracheal obstruction.