What is spectrum of squamous intraepithelial lesions?

In HSIL (CIN II), dysplasia extends to the middle third of the epithelium in the form of variation in cell and nuclear size, heterogeneity of nuclear chromatin, and the presence of mitoses, some atypical, above the basal layer extending into the middle third of the epithelium. The superficial layer of cells still shows differentiation and occasional koilocytotic changes HSIL (CIN III) is marked by almost complete loss of differentiation even greater variation in cell and nuclear size, chromatin heterogeneity, disorderly orientation of the cells, and abnormal mitoses, changes that affect virtually all layers of the epithelium. Koilocytotic change usually is absent.