Specific strains of the sexually transmitted human papillomavirus, or HPV, cause the benign tumors known as genital warts. HPV can also affect the cervix, the opening of the uterus, causing warts or changes in the appearance of cervical cells. Some strains of HPV classified as high-risk can cause cervical cancer, but most high-risk infections go away without treatment.
Warts
Some strains of HPV cause genital warts. Warts can appear on the cervix, as well as on and near the genitals. The warts are generally moist and flesh colored. They vary in size and can be flat or raised or appear in bunches that resemble cauliflower. Cervical warts rarely cause pain, but in some cases the cervix might feel sore. If left untreated, the warts might disappear, remain the same or grow in size or number, but the National Cancer Institute says that in most cases your body will fight off the virus over time, and the warts will disappear.
Atypical Cervical Cells
Infection with HPV can cause changes in the appearance of the cells lining the cervix, called squamous cells. A Pap smear will identify these changes. A positive Pap smear means that the lab found abnormalities. When some cervical squamous cells appear atypical in size, shape or color, the Pap smear will report ASC-US (some atypical squamous cells, undetermined significance), ASC-H (atypical squamous cells, cannot exclude a high-grade lesion) or LSIL (low-grade squamous intraepithelial lesion). Most women with an HPV infection will have these cellular changes for only a few months to a year after the infection, according to the NCI. Most types of HPV do not cause cervical cancer, and even in cases of infection with high-risk strains, the body's immune response usually eliminates or suppresses the virus so that the next Pap smear shows only normal cells.
Pre-Cancerous Lesions
Pre-cancerous cervical cells show clearly abnormal changes in the size, shape or color of cervical squamous cells that indicate some risk that they could develop into cancer. The cells are classified as HSIL (high-grade squamous intraepithelial lesion). The cells might have large empty spaces called vacuoles, and there might be changes in the appearance of the nucleus, which houses the cell's DNA, according to the Merck Manual. The cells are considered pre-cancerous because there is some risk that they will turn into cancer.
Cancer
Persistent infection for two years or more with a high-risk strain of HPV can cause cervical cancer. High-risk strains include HPV-16, 18, 31, 33, 35 and 39. Over 70 percent of cases of cervical cancer are associated with HPV strains 16 and 18. A woman with early-stage cervical cancer usually does not notice any symptoms, but characteristic changes in the squamous cells appear on a Pap smear, coded as CIN (cervical intraepithelial neoplasia) and graded according to how far the cancer has spread.
