Disorders of the Endocrine System

Epithelial cysts are common in the thyroid and pituitary in many strains of micc. Thyroid cysts are often lined by ciliated cells. A high prevalence of virgin inbred FVB/ NCr mice have been reported to develop prolactin­secreting foci of hyperplasia and adenomas of the pitui­tary pars distalis. These lesions are associated with lobulo-alveolar hyperplasia of mammary tissue in virgin females and spontaneous mammary tumors in aged multiparous females.