Cervical Intraepithelial Neoplasia: Overview and More

Only a pap test can detect abnormal cell growth on the outer cervix lining

Table of Contents
View All
Table of Contents

Cervical intraepithelial neoplasia (CIN), also known as cervical dysplasia, is the abnormal growth of cells (neoplasia) or lesions on your outer cervix lining (intraepithelial). CIN can be detected through your routine pap smear exam and is most commonly caused by one of the 100 subtypes of human papillomavirus (HPV).

CIN is also considered “premalignant” cancer, because having CIN is a risk factor for developing cervical cancer at a later time. Depending on your age, risk factors for cervical cancer, and health condition, treatment protocols can vary. 

What to Know About CIN

Verywell / Jessica Olahs

Cervical Intraepithelial Neoplasia (CIN) Symptoms

Cervical intraepithelial neoplasia can happen without you knowing it, because there are typically no symptoms. This is why getting routine pap smears is so important—only a pap smear will show the abnormal cells.

Further classification will occur after the diagnosis to specify the amount of tissue affected. The three grade levels of CIN include:​​

  • Low-grade neoplasia (CIN 1) involves about one-third of the thickness of the epithelium.
  • CIN 2 refers to abnormal changes in about one-third to two-thirds of the epithelial layer.
  • CIN 3 (the most severe form) affects more than two-thirds of the epithelium.

Postcoital Bleeding Could Signal CIN

If you have vaginal bleeding or spotting after engaging in penetrative or oral sexual activity, talk to your doctor. While not a hard and fast rule, research suggests this may be an predictor or sign of CIN. It may also indicate an infection like HPV that causes CIN. While there could be many other reasons, it’s best to get it checked out—especially if you’re due for a pap or HPV test.

Causes

Cervical intraepithelial neoplasia is most commonly caused by variations of HPV (i.e., HPV16 and HPV18) infecting a woman’s reproductive tract. The World Health Organization says these two HPV types (16 and 18) cause 70% of cervical cancers and precancerous cervical lesions.

Some risk factors also increase your likelihood of coming into contact with HPV, but you should know it’s a pretty common virus. Estimates say more than three-quarters of all sexually active women will become infected with HPV at some point in their lifetime.

Additional risk factors include:

  • Age (approximately 50% of HPV infections occur in girls and women between ages 15 to 25)
  • Smoking cigarettes
  • Taking immunosuppressant drugs 
  • Having unprotected sex
  • Having sex with multiple people
  • Sexual activity before age 18

You can help protect yourself against HPV infection by getting vaccinated.

Diagnosis

If your pap smear results show abnormal cells, your doctor or doctor’s office will contact you to discuss next steps. While this is an understandably upsetting experience, precancerous cells don’t typically become cancerous for years, if at all.

The next step is often to get an actual look at what’s happening via colposcopy so your doctor can examine the cervix area under a microscope. 

The colposcopy can be completed in your doctor’s office and can also be used to examine for:

  • Growths or lesions
  • Inflammation
  • Warts

From here, your doctor can decide if they need to take a biopsy or whether or not close monitoring (more frequent pap smears) is enough for now. DNA testing may also be done to see if you have a high-risk form of HPV.

If your HPV status is unknown, be aware that screening guidelines do recognize HPV testing as a method of detecting and preventing CIN and cervical cancer (in women age 30 and over). Getting tested is a part of determining your overall risk and what treatment method is most suitable.

The 2019 American Society for Colposcopy and Cervical Pathology (ASCCP) Risk-Based Management Consensus Guidelines for the management of cervical cancer screening abnormalities says recommendations for specific tests including colposcopy are based on a risk assessment, not pap smear results.

Treatment

Treatment may not be necessary in cases of low-grade CIN 1 because the underlying infection often resolves on its own. For higher-grade disease, the cells may need to be destroyed or removed to keep them from multiplying or mutating years from now.

If you have a more severe grade of CIN (2 or 3), treatment options include:

  • Cone biopsy to remove abnormal tissues; used for both therapeutic and diagnostic purposes
  • Cryotherapy (cold therapy) to freeze and remove abnormal tissues
  • Laser therapy or laser ablation to destroy abnormal cells
  • Loop electrosurgical procedure (LEEP), which uses an electricity-heated, thin, wire loop to remove abnormal tissue from the cervix

Research on alternative treatments or potential contributing factors that can be manipulated for therapeutic reasons is also being conducted.

One such study looked at how the presence or absence of Lactobacillus spp. (a common probiotic) altered the vaginal environment. Lower levels were associated with lower disease regression rates in 12- and 24-month follow-ups, suggesting some link which needs further examination.

Prognosis 

The prognosis of CIN will depend upon two factors:

  • The level of severity of abnormal cell coverage on your cervix upon discovery from pap smear. This is why detecting these cells as early as possible is best (the cells have less opportunity to multiply or mutate). 
  • Your ability and willingness to follow the ASCCP recommendations

What Are the ASCCP Recommendations?

The ASCCP recommends using one of six clinical actions to manage cervical cancer screening abnormalities based on the risk of developing CIN 3. These include:

  • Treatment
  • Optional treatment or colposcopy/biopsy
  • Colposcopy/biopsy
  • One-year surveillance
  • Three-year surveillance
  • Five-year return to regular screening

View full details on the recommendations based on risks.

While CIN isn’t cancer, it’s still a medical condition requiring your attention to support a positive prognosis. If you’re unsure of when your last pap was or how to get one, call your doctor’s office, a community health clinic, the local health department, or your local Planned Parenthood health center.

A Word From Verywell

It can be scary when you get a pap smear back with abnormal results, but most of the time there is nothing to worry about. Especially when discovered early on, the risk of these cells developing into cancer is fairly low.

Still, leaving something like this untreated is not recommended. You can protect yourself by making pap smears part of your healthcare routine and by following through with your doctor’s recommendations.

Frequently Asked Questions

  • Can you get pregnant after a LEEP?

    You will need some time to recover (full cervix recovery takes six months) before trying to get pregnant. The LEEP procedure does pose a small risk of some scarring over the cervical opening which may provide additional challenge for sperm to pass through, but this is rare.

  • Is CIN contagious?

    No, CIN is not contagious. It cannot be passed on to other people.

  • How did I get HPV?

    People can become infected with HPV by having vaginal, anal, or oral sex with someone who has the virus. You may not see signs or symptoms, but the virus can still be passed on. You do not need to have multiple sexual partners to get HPV. It can happen even if you’ve only had sex with one person.

Was this page helpful?
8 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Wright JD. Cervical intraepithelial neoplasia. UpToDates. Updated July 29, 2021.

  2. Cleveland Clinic. Cervical intraepithelial neoplasia (CIN). Updated May 7, 2014.

  3. Cohen O, Schejter E, Agizim R, et al. Postcoital bleeding is a predictor for cervical dysplasia. PLOS ONE. 2019;14(5):e0217396. doi:10.1371/journal.pone.0217396

  4. World Health Organization. Human papillomavirus (HPV) and cervical cancer.

  5. Perkins RB, Guido RS, Castle PE, et al. 2019 ASCCP risk-based management consensus guidelines for abnormal cervical cancer screening tests and cancer precursorsJ Low Genit Tract Dis. 2020;24(2):102-131. doi:10.1097/LGT.0000000000000525

  6. National Cancer Institute. CIN 2

  7. Mitra A, MacIntyre DA, Ntritsos G, et al. The vaginal microbiota associates with the regression of untreated cervical intraepithelial neoplasia 2 lesions. Nat Commun. 2020;11(1):1999. doi:10.1038/s41467-020-15856-y

  8. Johns Hopkins Medicine. Fertility and pregnancy after a LEEP.