Severe dysplasia means that the skin of the cervix is growing so rapidly that the immature basal cells extend completely through the skin thickness to the surface with any maturation. This is evidenced on the Pap smear as many completely immature cells appearing on the slide. This condition, a high grade intraepithelial problem, is also known as "CIN III." (Cervical Intraepithelial Neoplasia, Grade III), or "carcinoma-in-situ."

This is not cancer, but the only reason it isn't cancer is because the immature cells have not started growing (invading) beneath the epithelium into the underlying tissues. Because it is only one step away from invasive cancer, this is a very dangerous condition requiring treatment.

Treatment might consist of eliminating the dysplastic cells by freezing them (cryosurgery), vaporizing them (laser), or shaving them off with an electrified wire loop (LEEP). In some circumstances, more extensive surgery in the form of a cervical cone biopsy is required to eliminate the problem.