Cervical Dysplasia

Reviewed on 2/2/2022

Facts You Should Know About Cervical Dysplasia

  • Cervical dysplasia is precancerous changes of the cells that make up the lining of the cervix, the opening to the womb (uterus).
  • These changes are detected by microscopic analysis of cell samples taken from the cervix during a pelvic exam (such as from a Pap smear).
  • Squamous intraepithelial lesion is the pathology term used to refer to cervical dysplasia observed in smears of cells taken from the cervix.
  • Squamous refers to the type of cells on the cervix; intraepithelial refers to the fact that these cells are present in the lining tissue of the cervix.
  • When cervical dysplasia is seen in a biopsy of tissue rather than a cell smear, it is referred to as cervical intraepithelial neoplasia.

What Are Cervical Dysplasia Symptoms and Signs?

Cervical dysplasia is not typically associated with any symptoms; therefore, regular cervical cancer screening with a PAP smear and pelvic examination is recommended.

What Causes Cervical Dysplasia?

Cervical dysplasia is caused by infection with the human papillomavirus (HPV). HPV is a very common infection that is transmitted through sexual contact. Most new HPV infections occur in young (ages 15-25) women. Most HPV infections do not produce any symptoms and resolve spontaneously.

Some HPV infections persist over time rather than resolve, although the reason why this happens is not clear. Persistent HPV infection may lead to the development of genital warts, precancerous changes (cervical dysplasia) of the uterine cervix, as well as cervical cancer. Since not all women who have HPV infection develop cancer, additional factors must also be present to cause cervical dysplasia and cancer.

Certain HPV types typically cause genital warts or mild dysplasia ("low-risk" types; HPV-6, HPV-11), while other types (known as "high-risk" HPV types) are more strongly associated with severe dysplasia and cervical cancer (HPV-16, HPV-18).

Since HPV infections are transmitted primarily by sexual contact, the risk of infection increases with the number of sexual partners a person has. Cigarette smoking and suppression of the immune system (such as with HIV infection) are also known to increase the risk for HPV-induced dysplasia and cancer.

When Should I Call My Doctor if I Think I May Have Cervical Dysplasia?

The US Preventive Services Task Force has recommended the following screening policy for women regarding cervical dysplasia and cervical cancer screening:

  • Women should have their first Pap test at age 21 and should receive a Pap test every 3 years.
  • Women over age 30 may be screened every 5 years if an HPV test performed along with the Pap smear is negative.
  • Women over age 65 who have had at least three consecutive negative Pap tests or at least two negative HPV tests within the previous 10 years do not need to be screened.

What Tests and Procedures Diagnose Cervical Dysplasia?

Screening tests

Traditionally, the Papanicolaou test (Pap test or Pap smear) has been the screening method of choice for detecting cervical dysplasia. For this test a sample of cells from the surface of the cervix is removed by the healthcare practitioner during a pelvic examination with a speculum in place for visualization. The cells are placed into a vial of liquid that is later used to prepare a microscope slide for examination.

If the screening tests show abnormal appearing (dysplastic) cells, the results are given as one of the following categories:

  • LSIL: Low-grade squamous intraepithelial lesion, or changes characteristic of mild dysplasia.
  • HSIL: High-grade squamous intraepithelial lesion, corresponding to severe precancerous changes.
  • ASC: Atypical squamous cells. One of two choices are added at the end of ASC: ASC-US, which means undetermined significance, or ASC-H, which means cannot exclude HSIL (see above).

Further testing may be required if the screening test is abnormal. Further tests may include:


Colposcopy, or a procedure that uses a microscope to visualize the cervix during a pelvic exam. Colposcopy can help identify abnormal areas on the cervix and is a safe procedure with no complications other than occasional mild vaginal spotting.


Biopsies, or tissue samples for examination under the microscope, may be taken of suspicious areas seen during colposcopy.

When dysplasia is identified in tissue biopsies of the cervix, the term cervical intraepithelial neoplasia (CIN) is used. CIN is classified according to the extent to which the abnormal, or dysplastic, cells are seen in the cervical lining tissue:

  • CIN 1 refers to the presence of dysplasia limited to the basal 1/3 of the cervical lining, or epithelium (formerly called mild dysplasia).
  • CIN 2 is considered to be a high-grade (more serious) lesion. It refers to dysplastic cellular changes confined to the basal 2/3 of the lining tissue (CIN 2 was formerly called moderate dysplasia).
  • CIN 3 is also a high grade lesion. It refers to precancerous changes in the cells encompassing greater than 2/3 of the cervical lining up to and including full-thickness lesions. These were formerly referred to as severe dysplasia and carcinoma in situ.

HPV testing to detect whether or not HPV infection with a "high-risk" HPV type is present may be recommended for some women, particularly in the case of uncertain results from a screening test (as with smears interpreted as ASC-US, see above). Because a large number of women are infected with HPV and because the infection can be temporary and short-lived, regular screening of all women for HPV infection is not felt to be useful and is not routinely performed in the U.S.

What Is the Treatment for Cervical Dysplasia?

Most women with low grade (mild) dysplasia (LGSIL or CIN1) will undergo spontaneous regression of the mild dysplasia without treatment. Therefore, monitoring without specific treatment is often indicated in this group when the diagnosis is confirmed and all abnormal areas have been visualized. Surgical treatment is appropriate for women with high-grade cervical dysplasia.

When Is Surgery Necessary to Treat Cervical Dysplasia?

Treatments for cervical dysplasia fall into two general categories: 1) destruction (ablation) of the abnormal area, and 2) removal (resection). Both types of treatment are equally effective.

Destruction (ablation)

The destruction (ablation) procedures for treatment of cervical dysplasia include carbon dioxide laser photoablation and cryocautery. These treatments use a laser or freezing methods to remove the abnormal cells. The most common complications of ablation procedures are narrowing (stenosis) of the cervical opening and bleeding. Disadvantages of this treatment include that this procedure does not allow sampling of the abnormal area and is not satisfactory for treating cervical cancer. Clear vaginal discharge and spotting of blood can occur for a few weeks after these procedures. These procedures are used much less often now.

Removal (resection)

The removal (resection) procedures are loop electrosurgical excision procedure (LEEP), cold knife conization, and hysterectomy.

  • Loop electrosurgical excision procedure, also known as LEEP, is an inexpensive, simple procedure that uses a radio-frequency current to remove abnormal areas. With this and other removal procedures, an intact tissue sample for analysis can be obtained.
  • A cone biopsy is the surgical removal of abnormal areas using conventional surgical tools. Vaginal discharge and spotting commonly occur after these procedures.
  • Hysterectomy, or the surgical removal of the uterus, is used to treat almost all cases of invasive cervical cancer and may sometimes be used to treat severe dysplasia or dysplasia that recurs after any of the other treatment procedures.

Is There a Vaccine Against Cervical Dysplasia?

Gardasil was approved by the FDA for use in males and females aged 9-26. This vaccine has been shown to be safe and 100% effective in preventing infection with the four most common HPV types (6, 11, 16, and 18) in women who have had no previous exposure to the virus. However, it is less effective in women who have already been infected with HPV, and it does not protect against all types of HPV infection.

Abstinence from sexual activity can prevent the spread of HPV infection, but some researchers believe that HPV infection might be transmitted from the mother to infant in the birth canal. Hand-genital and oral-genital spread of HPV is also possible. Condoms may decrease the risk of contracting HPV during sexual activity but are not 100% effective in preventing the infection. Spermicides and hormonal birth control methods do not prevent HPV infection. HPV is not found in or spread by bodily fluids or transplanted organs.

Is It Possible to Prevent Cervical Dysplasia?

Low-grade cervical dysplasia (LGSIL and/or CIN1) often spontaneously resolves without treatment, but follow-up screening is recommended. Untreated high grade cervical dysplasia may progress to cervical cancer over time. Surgical treatment of cervical dysplasia cures most women, meaning some will have a recurrence of the dysplasia after treatment that will require additional treatment.

Reviewed on 2/2/2022
Medically reviewed by Wayne Blocker, MD; Board Certified Obstetrics and Gynecology.


U.S. Preventive Services Task Force. "Cervical Cancer Screening."