the earliest microscopic change corresponding to cin is epithelial dysplasia, or surface lining, of the cervix, which is essentially undetectable by the woman. the majority of these changes occur at the squamocolumnar junction, or transformation zone, an area of unstable cervical epithelium that is prone to abnormal changes. cellular changes associated with hpv infection, such as koilocytes, are also commonly seen in cin. while infection with hpv is needed for development of cin, most women with hpv infection do not develop high-grade intraepithelial lesions or cancer. hpv is not alone enough causative.