Epithelial dysplasia, a term becoming increasingly referred to as intraepithelial neoplasia, is the sum of various disturbances of epithelial proliferation and differentiation as seen microscopically. Individual cellular features of dysplasia are called epithelial atypia.
The changes that occur in epithelial dysplasia include:
Epithelial cell dysplasia is divided into three categories of severity: mild, moderate, and severe. Epithelial dysplasia becomes microinvasive squamous cell carcinoma once the tumor begins to invade nearby tissue.