When a female is infected with a high-risk type of cervical human papillomavirus (HPV) (such as type 16, 18, 31, & 33), precancerous cell changes (or cervical dysplasia) may occur. Advanced forms of these changes, called cervical intraepithelial carcinoma (CIN) and cervical in situ (CIS), are considered preinvasive lesions. They develop in the transformation zone, where the squamous epithelium and columnar epithelial cell layers meet within the cervix
(Danhausen, Phillippi, & McCance, 2019)
Most HPV infections resolve on their own or the cellular lesions remain preinvasive or non-cancerous.
In other situations, the abnormal cellular changes, which create high rates of cell division and increased presence of local mutagens, progress to invasive carcinoma and metastasis (Rote, 2019)