High-grade Squamous Intraepithelial Lesion (CIN III, Carcinoma-in-situ)
Image Description
Infection with human papilloma virus (usually the high-risk subtypes 16 & 18) is the main predisposing factor for the development of squamous intraepithelial lesions. The image shows nuclear atypia in all the epithelial layers and loss of maturation. Numerous mitotic figures are present, including some that are close to or at the surface.