| Type | MGI:General | Description | mammary glands of virgin females are 30-40% larger in size starting at 4 weeks of age mammary gland size is increased due to an increas in size of each cell not due to an increase in the number of epithelial cells mammary glands show numerous hyperplastic, noninvasive focal lesions resembling mammary intraepithelial neoplasia, seen as early as 5 months of age, irrespective of reproductive history squamous metaplasia and squamous cysts with central keratin debris are frequently seen |
