Last reviewed 10/2020
Cervical squamous epithelial dysplasia is characterised by:
- basal hyperplasia - multi-layering of basal cells
- nuclear pleomorphism
- increased mitotic activity
Three grades are described:
- CIN 1 - dysplasia limited to the basal one third of the squamous epithelium; previously referred to as "mild dysplasia"
- CIN 2 - dysplasia extends into the middle third of the epithelium; previously, "moderate dysplasia"
- CIN 3 - dysplasia extends into the upper third of the epithelium; previously, "severe dysplasia". The cells are virtually indistinguishable from frankly invasive carcinoma but the basement membrane remains intact