NCIt definition : A precancerous neoplastic process that affects the cervical squamous epithelium. It
is usually associated with human papillomavirus infection. It is classified as cervical
squamous intraepithelial neoplasia 2 when there is nuclear atypia in both the upper
and lower epithelial layers, mitotic figures are confined to the basal two-thirds
of the epithelium, and maturation is present in the upper half of the epithelium.
It is classified as cervical squamous intraepithelial neoplasia 3 when there is nuclear
atypia and mitotic figures throughout the entire thickness of the epithelium, and
maturation is absent or confined to the upper third of the epithelium.;