Cervical dysplasia is a precancerous condition in which abnormal cell growth occurs on the surface lining of the cervix or endocervical canal, the opening between the uterus and the vagina. It is also called cervical intraepithelial neoplasia (CIN). Strongly associated with sexually transmitted human papillomavirus (HPV) infection, cervical dysplasia is most common in women under age 30 but can develop at any age.
Cervical dysplasia usually causes no symptoms, and is most often discovered by a routine Pap test. The prognosis is excellent for women with cervical dysplasia who receive appropriate follow-up and treatment. But women who go undiagnosed or who don't receive appropriate care are at higher risk of developing cervical cancer.
Cervical cancer is cancer of the cervix, the narrow neck at the lower part of a woman's uterus, just above the vagina (Figure 1). The cervix connects the uterus to the vagina.
Approximately eight out of 10 cervical cancers originate in surface cells lining the cervix (squamous cell carcinomas). These cancers do not form suddenly. Over time, healthy cervical cells can become abnormal in appearance -- this is called dysplasia. Although these cells are not cancerous, they can eventually become...
Mild cervical dysplasia sometimes resolves without treatment, and may only require careful observation with Pap tests every three or six months. But moderate-to-severe cervical dysplasia -- and mild cervical dysplasia that persists for two years -- usually requires treatment to remove the abnormal cells and reduce the risk of cervical cancer.
Causes of Cervical Dysplasia
In many women with cervical dysplasia, HPV is found in cervical cells. HPV infection is common in women and men, and most often affects sexually active women under age 20.
In most cases, the immune system eliminates HPV and clears the infection. But in some women, the infection persists and leads to cervical dysplasia. Of the more than 100 different strains of HPV, more than one-third of them can be sexually transmitted, and two particular types -- HPV 16 and HPV 18 -- are strongly associated with cervical cancer.
HPV is usually passed from person to person during sexual contact such as vaginal intercourse, anal intercourse, or oral sex. But it also can be transmitted by any skin-to-skin contact with an infected person. Once established, the virus is capable of spreading from one part of the body to another, including the cervix.
Among women with a chronic HPV infection, smokers are twice as likely as nonsmokers to develop severe cervical dysplasia, because smoking suppresses the immune system.
Chronic HPV infection and cervical dysplasia are also associated with other factors that weaken the immune system, such as treatment with immunosuppressive drugs for certain diseases or after an organ transplant, or infection with HIV, the virus that causes AIDS.