Morphological changes in mice thyroid induced by iodine deficiency.

Goitrogenesis induced in mice by iodine deficiency took place in two distinct phases. The first phase lasted four weeks and was characterized histologically by the classic signs of hyperplasia: colloid resorption, increase in the height of the epithelium and enlargment of the capillaries. After the fourth week, the morphological changes in the thyroid were different in males and females. In the male, pluristratified follicles, secondary follicular cavities and papillary projections were observed. In the female, most of the follicles retained their hyperplastic appearance, while papillary projections were observed in very few follicles.