Cervical Dysplasia: Causes, Screening & Treatment

What Is Cervical Dysplasia?

Cervical dysplasia is a condition where abnormal cells develop on the surface lining of the cervix (the lower part of the uterus). It is caused by persistent infection with human papillomavirus (HPV) and is detected through routine cervical screening. While not cancer itself, some types can progress to cervical cancer if left untreated over many years.

The cervix is the narrow, lower portion of the uterus that connects to the vagina. The surface of the cervix is covered by two types of cells: squamous cells on the outer portion and glandular cells lining the cervical canal. The area where these two cell types meet, called the transformation zone, is where most cervical dysplasia develops. This is because the cells in this area are constantly changing and dividing, making them more susceptible to HPV infection and abnormal changes.

When cervical cells become infected with certain types of HPV, the virus can integrate into the cell's DNA and cause the cells to grow abnormally. These abnormal cells may look different under a microscope and behave differently than normal cells, but they remain confined to the surface layer of the cervix and have not invaded deeper tissues. This distinguishes dysplasia from invasive cancer, which has broken through the basement membrane and can spread to other parts of the body.

Cervical dysplasia is classified based on how much of the cervical epithelium (surface layer) is affected by abnormal cells. The classification system helps guide treatment decisions and predict the likelihood of the condition progressing or resolving on its own. Understanding these classifications is important because they determine whether watchful waiting or active treatment is recommended.

Classifications of Cervical Dysplasia

There are two main classification systems used to describe cervical dysplasia. The older system uses the term Cervical Intraepithelial Neoplasia (CIN), while the newer system uses Squamous Intraepithelial Lesion (SIL). Both systems categorize dysplasia by severity:

It is important to understand that cervical dysplasia, even high-grade lesions, is not cancer. The progression from dysplasia to invasive cervical cancer typically takes 10-20 years, providing ample opportunity for detection and treatment through regular screening. This slow progression is why screening programs have been so successful in reducing cervical cancer rates in countries where they are widely implemented.

What Causes Cervical Dysplasia?

Cervical dysplasia is caused primarily by persistent infection with high-risk types of human papillomavirus (HPV). HPV types 16 and 18 are responsible for approximately 70% of cervical cancers and most high-grade dysplasia. While most HPV infections clear on their own, persistent infections can lead to cellular changes over time.

Human papillomavirus is an extremely common sexually transmitted infection, with most sexually active people becoming infected at some point in their lives. There are over 200 types of HPV, but only about 14 are considered "high-risk" for causing cervical cancer. HPV 16 and HPV 18 are by far the most dangerous, together responsible for about 70% of all cervical cancers worldwide. Other high-risk types include HPV 31, 33, 35, 45, 52, and 58.

The mechanism by which HPV causes cervical dysplasia involves the virus's ability to integrate into the host cell's DNA. Once integrated, the virus produces proteins called E6 and E7 that interfere with the cell's normal regulatory processes. These proteins inactivate tumor suppressor genes (p53 and Rb), which normally prevent cells from dividing uncontrollably. Without these protective mechanisms, infected cells can begin to grow abnormally and eventually become dysplastic.

However, HPV infection alone is usually not sufficient to cause cervical dysplasia. The body's immune system clears most HPV infections within 1-2 years without causing any lasting damage. It is only when the infection persists and the virus integrates into the cell's DNA that dysplasia can develop. This is why factors that affect immune function or increase viral persistence play such an important role in the development of cervical dysplasia.

Risk Factors for Cervical Dysplasia

Several factors increase the risk of developing cervical dysplasia by either increasing exposure to HPV or reducing the body's ability to clear the infection:

• Smoking: Tobacco smoke contains carcinogens that concentrate in cervical mucus and damage cellular DNA. Smoking also suppresses local immune function in the cervix, making it harder for the body to clear HPV infections. Studies show that smokers are 2-4 times more likely to develop cervical dysplasia than non-smokers.
• Immunosuppression: Conditions or medications that weaken the immune system increase the risk of persistent HPV infection. This includes HIV infection, organ transplant recipients taking immunosuppressive drugs, and people on long-term corticosteroid therapy.
• Multiple sexual partners: Having more sexual partners increases the likelihood of exposure to HPV and other sexually transmitted infections. This is a risk factor for initial HPV acquisition rather than for progression of existing infections.
• Early age at first intercourse: The transformation zone of the cervix is particularly vulnerable to HPV infection during adolescence when cells are actively dividing. Starting sexual activity at a younger age increases cumulative exposure to HPV.
• Long-term oral contraceptive use: Some studies suggest that using oral contraceptives for more than 5 years may slightly increase cervical cancer risk, possibly by maintaining the transformation zone in an active state. However, this effect is small and the benefits of contraception generally outweigh this risk.
• Other sexually transmitted infections: Co-infection with Chlamydia trachomatis or herpes simplex virus type 2 may increase susceptibility to HPV or promote its persistence.

Does Cervical Dysplasia Cause Symptoms?

Cervical dysplasia typically causes no symptoms, which is why regular screening is essential for detection. Some people may notice abnormal vaginal bleeding or discharge, but these symptoms are more common with advanced dysplasia or early cancer. The absence of symptoms makes screening programs crucial for catching changes before they become dangerous.

One of the most important things to understand about cervical dysplasia is that it almost never causes symptoms in its early stages. The abnormal cells are confined to the surface layer of the cervix and do not typically cause pain, bleeding, or other noticeable changes. This is why cervical dysplasia is sometimes called a "silent" condition—you cannot feel it or know it is present without testing.

This lack of symptoms underscores the critical importance of regular cervical screening. Without screening, cervical dysplasia can progress undetected over many years until it becomes invasive cancer, at which point symptoms may finally appear. By the time symptoms develop, the cancer may be more advanced and more difficult to treat. Screening programs exist specifically to detect these changes when they are still easily treatable.

In some cases, particularly with more advanced dysplasia or early invasive cancer, symptoms may occur. These can include:

• Abnormal vaginal bleeding: This may occur between periods, after menopause, or after sexual intercourse. Post-coital bleeding (bleeding after sex) is particularly concerning and should always be evaluated.
• Unusual vaginal discharge: The discharge may be watery, bloody, or have an unusual odor. While many conditions can cause abnormal discharge, persistent changes should be reported to a healthcare provider.
• Pelvic pain: This is typically associated with more advanced disease rather than dysplasia itself.

How Is Cervical Dysplasia Detected?

Cervical dysplasia is detected through routine cervical screening, which includes Pap smears (cervical cytology) and HPV testing. These tests can identify abnormal cells or HPV infection before any symptoms develop. If screening results are abnormal, further evaluation with colposcopy and biopsy may be recommended.

Cervical cancer screening has been one of the most successful cancer prevention strategies in medical history. In countries with organized screening programs, cervical cancer rates have dropped by 70-80% over the past several decades. This dramatic reduction is possible because screening can detect precancerous changes years or even decades before cancer would develop, allowing for effective treatment.

Modern cervical screening typically involves two types of tests, which may be used alone or in combination depending on your age and local guidelines:

Pap Smear (Cervical Cytology)

The Pap smear, named after Dr. George Papanicolaou who developed it in the 1940s, involves collecting cells from the cervix and examining them under a microscope for abnormalities. During the test, a healthcare provider inserts a speculum into the vagina to visualize the cervix, then uses a small brush or spatula to gently collect cells from the transformation zone. The cells are either smeared on a glass slide (conventional Pap) or placed in a liquid preservative (liquid-based cytology) before being sent to a laboratory for analysis.

Pap smear results are reported using standardized terminology. Normal results are reported as "negative for intraepithelial lesion or malignancy." Abnormal results may include:

• ASC-US: Atypical squamous cells of undetermined significance—mildly abnormal cells that may or may not indicate HPV infection or dysplasia
• ASC-H: Atypical squamous cells, cannot exclude high-grade lesion—more concerning abnormalities that require further evaluation
• LSIL: Low-grade squamous intraepithelial lesion—indicates mild cellular changes, often corresponding to CIN 1
• HSIL: High-grade squamous intraepithelial lesion—indicates more significant changes that require treatment
• AGC: Atypical glandular cells—abnormalities in glandular cells, which may indicate problems higher in the cervical canal or uterus

HPV Testing

HPV testing detects the genetic material (DNA or RNA) of high-risk HPV types in cervical cells. The sample is collected in the same way as a Pap smear and can often be done from the same specimen. HPV testing is more sensitive than Pap smears for detecting women at risk of developing high-grade dysplasia or cancer, meaning it misses fewer cases. However, because HPV infections are so common and most clear on their own, HPV testing is generally recommended for women over 30 or as a follow-up to abnormal Pap results in younger women.

Current screening guidelines vary by country and may change based on emerging evidence. In general, screening recommendations include:

• Beginning screening at age 21-25, depending on guidelines
• Screening every 3-5 years, depending on the test used and previous results
• Continuing screening until age 65, after which it may stop if previous results have been consistently normal
• More frequent screening for those with abnormal results or increased risk factors

How Is Cervical Dysplasia Diagnosed?

If screening tests are abnormal, cervical dysplasia is definitively diagnosed through colposcopy—a procedure where the cervix is examined with a magnifying instrument and tissue samples (biopsies) are taken. The biopsies are analyzed by a pathologist who determines the type and severity of any dysplasia present.

When a Pap smear or HPV test returns abnormal results, further evaluation is needed to determine whether cervical dysplasia is present and, if so, how severe it is. The standard next step is colposcopy, a procedure that allows detailed examination of the cervix and targeted sampling of any abnormal areas.

What Is Colposcopy?

Colposcopy is an outpatient procedure performed by a gynecologist or specially trained healthcare provider. During the procedure, you lie on an examination table similar to a Pap smear, and a speculum is inserted to visualize the cervix. The colposcope—a large magnifying device similar to binoculars on a stand—is positioned outside the vagina and used to examine the cervix under magnification (typically 8-15 times normal size).

To enhance visualization of abnormal areas, dilute acetic acid (similar to vinegar) is applied to the cervix. Normal cells appear unchanged, while dysplastic cells turn white (acetowhite changes) because of their different protein content. The provider may also apply iodine solution (Schiller's test), which stains normal glycogen-containing cells brown while abnormal cells remain unstained. These techniques help identify areas that should be biopsied.

Small tissue samples (biopsies) are taken from any suspicious areas using specialized forceps. While you may feel a pinching or cramping sensation during biopsy, the procedure is usually well-tolerated without anesthesia. If the transformation zone extends into the cervical canal and cannot be fully visualized, an endocervical curettage (ECC) may be performed—a scraping of the inner cervical canal to collect cells from that area.

Understanding Your Results

The biopsy specimens are sent to a pathology laboratory where they are processed, stained, and examined under a microscope by a pathologist. It typically takes 1-3 weeks to receive results. The pathologist will report whether dysplasia is present and, if so, classify it as CIN 1, CIN 2, or CIN 3. The results guide treatment decisions:

• Normal/CIN 1: Often managed with observation and repeat testing, as many cases resolve spontaneously
• CIN 2: Treatment is usually recommended, though observation may be appropriate in certain circumstances (young women, pregnancy)
• CIN 3: Treatment is recommended due to higher risk of progression to cancer

How Is Cervical Dysplasia Treated?

Treatment for cervical dysplasia depends on its severity. Low-grade dysplasia (CIN 1) often resolves on its own and may be monitored with repeat testing. High-grade dysplasia (CIN 2-3) is typically treated with excisional procedures such as LEEP or conization, which remove the abnormal tissue. Treatment is highly effective, with cure rates exceeding 90%.

The goal of treating cervical dysplasia is to remove or destroy all abnormal cells while preserving as much normal cervical tissue as possible. This is particularly important for women who wish to have children in the future, as removing too much cervical tissue can affect fertility and pregnancy outcomes. Modern treatment approaches balance the need to eliminate disease with the goal of minimizing harm.

Observation (Watchful Waiting)

For low-grade dysplasia (CIN 1) and sometimes for CIN 2 in young women, observation with repeat testing may be recommended rather than immediate treatment. This approach recognizes that many cases of low-grade dysplasia will resolve on their own as the immune system clears the underlying HPV infection. Studies show that 60-90% of CIN 1 cases regress spontaneously within 1-2 years.

During observation, you will have more frequent Pap smears and/or HPV tests (typically every 6-12 months) to monitor the dysplasia. If the abnormalities persist beyond a certain timeframe or progress to higher-grade lesions, treatment will be recommended. If the dysplasia resolves and HPV clears, you can return to routine screening intervals.

LEEP (Loop Electrosurgical Excision Procedure)

LEEP is the most commonly performed treatment for cervical dysplasia worldwide. Also known as LLETZ (Large Loop Excision of the Transformation Zone), this procedure uses a thin wire loop carrying electrical current to cut away the abnormal tissue. The electrical current simultaneously cuts the tissue and cauterizes blood vessels, minimizing bleeding.

LEEP is typically performed in an outpatient setting under local anesthesia. The cervix is numbed with an injection similar to dental anesthesia, and the entire transformation zone containing the abnormal cells is removed in one or more passes of the loop. The procedure usually takes 15-20 minutes, and most patients can return to normal activities within a day or two.

Advantages of LEEP include its effectiveness (cure rates over 90%), the ability to examine the removed tissue (providing additional diagnostic information), relatively low cost, and minimal impact on future fertility for most patients. The removed tissue is sent to pathology to confirm complete removal of the dysplasia and rule out invasive cancer.

Conization (Cone Biopsy)

Conization involves removing a cone-shaped piece of tissue from the cervix that includes both the transformation zone on the surface and part of the cervical canal. It is named for the cone shape of the specimen, with the point of the cone extending into the canal. Conization may be performed using a surgical knife (cold knife conization), LEEP, or laser.

Conization is typically reserved for situations where deeper tissue removal is needed, such as when the transformation zone extends into the cervical canal and cannot be fully visualized, when glandular abnormalities (adenocarcinoma in situ) are present, or when microinvasive cancer is suspected. The procedure may be performed under local or general anesthesia depending on the extent of tissue removal needed.

Other Treatment Options

Several other treatment methods may be used in specific circumstances:

• Cryotherapy: Freezing of abnormal tissue using liquid nitrogen. Less commonly used now due to lower effectiveness compared to excisional methods and inability to obtain tissue for analysis.
• Laser ablation: Destruction of abnormal tissue using a focused laser beam. May be used for large lesions or when preservation of cervical length is particularly important.
• Hysterectomy: Removal of the uterus is rarely needed for dysplasia but may be considered for recurrent high-grade lesions or when the patient has completed childbearing and has other reasons for hysterectomy.

Recovery After Treatment

Most patients recover quickly after excisional treatment for cervical dysplasia. Common post-procedure experiences include:

• Mild cramping: Similar to menstrual cramps, usually resolving within a few hours to days. Over-the-counter pain relievers like ibuprofen or acetaminophen are usually sufficient.
• Vaginal discharge: A watery or blood-tinged discharge is normal for 2-4 weeks as the cervix heals. The discharge may have an unusual odor due to the healing process.
• Light bleeding: Spotting or light bleeding may occur, especially around 10-14 days post-procedure when the scab falls off.

During the healing period (typically 4-6 weeks), you should avoid vaginal intercourse, tampons, and douching to allow the cervix to heal and reduce infection risk. Most patients can return to work and normal activities within 1-2 days of the procedure.

What Happens After Treatment?

After treatment for cervical dysplasia, regular follow-up testing is essential to ensure the abnormal cells have been completely removed and to detect any recurrence. Most guidelines recommend testing at 6 months and 12 months after treatment, followed by annual screening for several years before returning to routine intervals.

Successful treatment of cervical dysplasia does not mean you no longer need cervical screening. Follow-up testing is crucial because approximately 5-15% of treated patients will have persistent or recurrent disease. The risk of recurrence is higher for those with larger or more severe lesions, involved margins on the excised specimen, or persistent high-risk HPV infection.

Follow-up typically involves a combination of Pap smear and HPV testing (co-testing) at 6 months post-treatment. If both tests are negative, testing is repeated at 12 months. If results remain negative, annual co-testing continues for several years (often 3-5 years) before returning to routine screening intervals. If abnormalities are detected during follow-up, colposcopy and possible retreatment may be recommended.

The good news is that most patients who complete treatment and follow-up have excellent long-term outcomes. The risk of developing cervical cancer after successful treatment of dysplasia is very low when proper follow-up is maintained. However, the risk remains slightly higher than someone who never had dysplasia, which is why continued surveillance is important.

Does Cervical Dysplasia Affect Pregnancy?

Cervical dysplasia itself does not affect fertility or the ability to become pregnant. However, treatments that remove cervical tissue may slightly increase the risk of preterm birth in future pregnancies. Most women who have been treated for cervical dysplasia go on to have normal pregnancies, though closer monitoring may be recommended.

One of the concerns for women of reproductive age diagnosed with cervical dysplasia is the potential impact on future fertility and pregnancy. It is important to understand the distinction between the dysplasia itself and its treatment when considering these effects.

Cervical dysplasia does not affect your ability to conceive or carry a pregnancy. The abnormal cells are confined to the surface of the cervix and do not interfere with ovulation, fertilization, or implantation. If you are diagnosed with low-grade dysplasia during pregnancy, it is usually safe to monitor the condition and defer treatment until after delivery, as many cases will resolve on their own.

Treatment for cervical dysplasia, however, can have implications for future pregnancies. Procedures like LEEP and conization remove cervical tissue, which can shorten and weaken the cervix. The cervix plays an important role in pregnancy, providing structural support to keep the uterus closed until delivery. A significantly shortened cervix may be associated with:

• Cervical insufficiency: The cervix opens too early in pregnancy, potentially leading to pregnancy loss or preterm birth
• Preterm labor and delivery: Higher risk of delivering before 37 weeks of pregnancy
• Low birth weight: Babies born early may have lower birth weights

However, it is important to keep these risks in perspective. The absolute increase in preterm birth risk after a single LEEP is relatively small (studies suggest the risk increases from about 6% to 8-10%). The risk is higher when more tissue is removed, such as with larger excisions or multiple treatments. For most women, the benefits of treating high-grade dysplasia to prevent cervical cancer far outweigh the potential pregnancy risks.

If you have been treated for cervical dysplasia and become pregnant, inform your healthcare provider about your history. Depending on how much tissue was removed and your cervical length, additional monitoring or interventions (such as cervical length screening or cerclage placement) may be recommended to help ensure a healthy pregnancy.

How Can I Prevent Cervical Dysplasia?

HPV vaccination is the most effective way to prevent cervical dysplasia, reducing cervical cancer risk by up to 90% when given before HPV exposure. Other prevention strategies include not smoking, practicing safer sex, and attending regular cervical screening. Even after treatment for dysplasia, vaccination may help prevent new infections with other HPV types.

Prevention of cervical dysplasia focuses on two main strategies: preventing HPV infection in the first place and detecting any changes early through regular screening. Both approaches have been remarkably successful in reducing cervical cancer rates worldwide.

HPV Vaccination

HPV vaccines are one of the most significant advances in cancer prevention. Current vaccines protect against the HPV types responsible for the vast majority of cervical cancers and high-grade dysplasia. The vaccines are most effective when given before exposure to HPV, which is why they are typically recommended for children and young adults aged 9-26.

There are currently several HPV vaccines available globally. The most widely used vaccine protects against nine HPV types: two that cause most cervical cancers (types 16 and 18), five others associated with cancer (types 31, 33, 45, 52, and 58), and two that cause genital warts (types 6 and 11). Together, these nine types are responsible for approximately 90% of cervical cancers.

Studies have demonstrated dramatic reductions in HPV infection and cervical dysplasia in vaccinated populations. Countries with high vaccination coverage are already seeing significant decreases in high-grade dysplasia among young women. Long-term studies suggest the vaccine provides protection for at least 10-15 years, and ongoing research continues to monitor duration of protection.

Even if you have already had cervical dysplasia, HPV vaccination may still be beneficial. The vaccine can protect against other HPV types you may not have been exposed to, potentially reducing the risk of new infections and recurrent disease. Discuss with your healthcare provider whether vaccination is appropriate for you.

Lifestyle Factors

Several lifestyle modifications can reduce your risk of cervical dysplasia or help existing dysplasia resolve:

• Quit smoking: Smoking significantly increases the risk of cervical dysplasia and impairs your body's ability to clear HPV infections. Quitting smoking at any time is beneficial—studies show that dysplasia is more likely to resolve in those who quit compared to those who continue smoking.
• Practice safer sex: While condoms do not completely prevent HPV transmission (the virus can infect areas not covered by condoms), consistent condom use does reduce HPV acquisition and may help clear existing infections.
• Limit number of sexual partners: Reducing the number of sexual partners decreases exposure to HPV and other sexually transmitted infections.
• Maintain a healthy immune system: A strong immune system is better able to clear HPV infections before they can cause cellular changes. This includes eating a balanced diet, exercising regularly, getting adequate sleep, and managing stress.

Regular Screening

Perhaps the most important prevention strategy is attending regular cervical screening appointments. Screening cannot prevent HPV infection or the initial development of dysplasia, but it can detect changes at an early, easily treatable stage—long before they could become cancer. Follow your healthcare provider's recommendations for screening frequency based on your age, risk factors, and previous results.