Low-grade squamous intraepithelial lesion (LSIL) is a common abnormal result on a Pap test. It’s also known as mild dysplasia. LSIL means that your cervical cells show mild abnormalities. A LSIL, or abnormal Pap result, doesn’t mean that you have cancer.

The tissue that covers your cervix is made up of squamous cells. Pap tests are used to screen for cervical cancer, pre-cancer, and other cervical cell abnormalities.

Most women who have abnormal cervical screening test results do not have cervical cancer. Your doctor may recommend follow-up testing, but LSIL sometimes clears up on its own.

Keep reading to learn more about LSIL, as well as what to expect in the way of symptoms, follow-up tests, and treatment options.

LSIL does not have any symptoms. In fact, you probably wouldn’t know you have abnormal cells on your cervix until you’ve had a Pap test. For that reason, regular screenings are important for early diagnosis and treatment.

Cervical cancer screening recommendations

The U.S. Preventive Services Task Force recommends the following screening guidelines for cervical cancer:

  • Age 21–29: Pap test every 3 years
  • Age 30–65: HPV test alone every 5 years, or Pap/HPV co-test every 5 years, or Pap alone every 3 years

You might need to be screened more often if you have HIV, a compromised immune system, or previous precancerous cervical lesions or cervical cancer.

LSIL is not cancer. While a Pap test is used to screen for cervical cancer, it can’t determine for sure that abnormal cells are cancerous. For that, you would need a cervical biopsy.

Pap tests can reveal precancerous cells and other abnormal changes that may lead to cervical cancer.

This is important because precancer can be treated so that you don’t develop cervical cancer. Most of the time, cervical cancer is found in women who have not had regular Pap tests.

LSIL is usually linked to human papillomavirus infection (HPV). Without treatment, HPV can sometimes progress to cervical cancer.

That’s why follow-up testing is so important. Keep in mind, though, that it takes 10 to 20 years or even longer for a high-risk HPV infection to become cancerous.

In about 10 percent of cases, LSIL progresses to high-grade squamous intraepithelial lesions (HSIL) within two years. This is more likely to occur in people who are 30 years old or older, compared to those in their 20s.

If you have HSIL, it means the changes to cervical cells are more severely abnormal. Without treatment, HSIL may develop into cervical cancer. At this point, your doctor might recommend other tests such as colposcopy and biopsy, and removal of the abnormal areas.

HSIL is also referred to as moderate or severe dysplasia.

Most people with LSIL test positive for HPV. Almost all cervical cancers are caused by HPV.

If your Pap results show mild abnormalities (LSIL), your doctor will base their treatment recommendations on your age, how many abnormal Pap tests you’ve had, and other cervical cancer risk factors.

Recommendations may include:

  • A repeat Pap test and HPV test either right away or in 12 months. These tests can be done at the same time.
  • An HPV type test to look for HPV types 16 or 18, which are the types generally associated with cervical cancer.
  • Colposcopy, a procedure in which your doctor examines the cervix with a magnifying device. The procedure is performed much like a pelvic exam. If suspicious tissue is seen during a colposcopy, a sample can be taken for biopsy.

If a second Pap test has abnormal results, you’ll need to repeat it again in 12 months. If you have normal results, you can probably go back to your regular screening schedule.

Because LSIL can progress to HSIL, and potentially to cancer, it’s important to follow through with testing as recommended.

According to a large 2017 study, most women with LSIL test positive for HPV. Approximately 90 percent of them fight off an HPVinfection (replacing abnormal cells with healthy tissue) within 2 years. This is especially true for teens and young women.

If HPV does not clear up on its own and Pap tests continue to show LSIL, abnormal cells can be removed.

Excisional treatment

Excisional treatment is one method doctors may recommend for removing abnormal cells.

In excisional treatment, cervical tissue is removed and sent to a laboratory for further analysis. There are two ways to do this:

Ablative treatment

Ablative treatment is another possible treatment your doctor may recommend. Ablative treatment destroys the abnormal tissue. It can be done in two ways:

  • Cryosurgery. Your doctor uses an instrument that freezes off the abnormal tissue.
  • Laser therapy. Your doctor destroys abnormal cervical tissue with a focused beam of light.

LSIL (and HPV infections) often clear up on their own without treatment. In these cases, no treatment or recovery is needed.

If your immune system is having a hard time fighting off the HPV infection, your doctor may recommend excisional treatment.

Excisional and ablative treatments are all outpatient procedures. You may have some discomfort for a few days. You can also expect some discharge for a few days to a few weeks, depending on the procedure. Your doctor may advise you not to have sex for several weeks following the procedure.

LSIL is not contagious, but HPV is a sexually transmitted disease (STD). This means you can spread it through vaginal, anal, or oral sex.

HPV is so common that almost everyone gets it at some point, but it usually clears up on its own. There aren’t always symptoms, so you might not know you have it.

If you’ve had LSIL, it doesn’t necessarily mean you’ll have it again, but it’s important to follow recommendations for future screening.

One way to prevent cervical cancer from developing is to have the recommended Pap screenings. That way, you’ll be able to treat abnormal cells before they become cancerous.

The U.S. Preventive Services Task Force recommends the following screening guidelines for cervical cancer:

  • Age 21–29: Pap test every 3 years
  • Age 30–65: HPV test alone every 5 years, or Pap/HPV co-test every 5 years, or Pap alone every 3 years

You might need to be screened more often if you have:

  • HIV
  • a compromised immune system
  • previous precancerous cervical lesions or cervical cancer

When screening is not necessary

It’s not necessary to screen for cervical cancer if you’ve had a total hysterectomy and have never had precancerous lesions or cervical cancer.

Talk to your doctor about the best screening schedule for you.

Another way to help prevent cervical cancer is to get the HPV vaccine. This vaccine doesn’t totally protect you from cervical cancer, so you’ll still need regular screening.

Other ways to help prevent cervical cancer are:

  • don’t smoke
  • always use a condom
  • limit your sex partners (to reduce possible exposure to HPV)

LSIL often resolves on its own or can be effectively treated to help prevent development of cervical cancer.

Although LSIL is not cancer, regular (and follow-up, if needed) Pap screenings are important in order to identify and treat abnormal cells before they become cancerous.