High Grade Squamous Intraepithelial Lesion Treatment

An abnormal Pap smear result of high-grade squamous intraepithelial lesion (HSIL) means that cells of the cervix (the narrow neck of a woman's uterus) look somewhat to very abnormal when examined under a microscope.

Before cervical cancer forms, the cells of the cervix undergo abnormal changes called cervical dysplasia. Although untreated cervical dysplasia can lead to cervical cancer, having it does not mean that a person has cancer or will develop the disease.

Additional testing is typically needed for HSIL to confirm cervical dysplasia and to learn more about the severity of the abnormal cells. It may be treated first with monitoring to see if it persists or with an outpatient procedures in the healthcare provider's office.

According to the Centers for Disease Control and Prevention, up to 93% of cervical cancers are preventable with regular screening and treatment of abnormalities that arise. This is why women undergo regular Pap smear exams to screen for any abnormal changes to the cervix.

Pap smear medical test
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HSIL Pap Smear Results

An HSIL Pap smear result indicates that more defined changes in the size and shape of cervical cells have been detected, which indicates there is likely moderate-to-severe cervical dysplasia.

HPV testing is most often done along with a Pap smear, and if it was not done, should be performed on the sample. This testing looks for the high-risk forms of HPV that can lead to cervical cancer, including HPV 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, and 68, with HPV 16 and 18 most commonly found. The vast majority of cervical cancers are caused by these HPV infections.

An HSIL Pap smear result cannot confirm whether or not precancerous or cancerous changes are present, and further testing is needed.

Further Testing

Pap smear screening results, such as HSIL, aren't enough to make a diagnosis and plan treatment (they represent only a sampling of cells). If Pap smear results come back as HSIL, your healthcare provider may recommend a colposcopy exam and biopsy. This is true whether or not an HPV test is positive or negative.

A colposcopy exam is an in-office procedure that allows a healthcare provider to visually examine the cervix with a lighted instrument called a colposcope. During the exam, the colposcope remains outside of the vagina. It acts like a microscope, allowing an in-depth view of the cervix.

During the colposcopy, the healthcare provider may also do a cervical biopsy, a procedure that removes small pieces of cervical tissue. The tissue samples are then sent to a lab for further examination. Think of a colposcopy as a more in-depth Pap smear.

A biopsy result obtained during a colposcopy allows a pathologist to see the actual changes in cells and their relation to each other within the tissue. This is needed to confirm whether or not precancerous changes or cancer are present.

HSIL on a screening Pap smear usually corresponds to cervical intraepithelial neoplasia (CIN), which are precancerous cells that are graded based on how abnormal the cells appear under a microscope. The grades of CIN are:

  • CIN 1 (grade 1): Also called low-grade or mild dysplasia, there are slightly abnormal cells found on the cervix.
  • CIN 2 (grade 2): Moderately abnormal cells have formed on the cervix.
  • CIN 2/3: Both moderately abnormal and severely abnormal cells are on the cervix.
  • CIN 3 (grade 3): Also called severe or high-grade dysplasia, there are severely abnormal cells found on the cervix.

CIN 1 usually goes away on its own without treatment, but in some cases it can spread or turn into cancer. CIN 2 is more likely to spread and turn into cancer than CIN 1 and treatment may be needed. CIN 2/3 or CIN 3 are grades that typically require prompt treatment.

Cervical biopsies can sometimes reveal adenocarcinoma in situ (AIS), which means there are abnormal glandular cells that have not spread beyond where they formed. AIS is sometimes referred to as stage 0 cancer. When AIS if found or cervical cancer is caught at an early stage, it's easier to treat and the survival rates are highest. Treatments for AIS are often similar to those for severe dysplasia.


When choosing the best treatment for a HSIL Pap smear result, healthcare providers look at the risk of CIN 3 being present. To do so, they look at your current tests, your history of cervical cancer screening, your past medical history, your age, and whether you plan to become pregnant in the future or are pregnant at the current time.

Expedited Treatment

If the risk of CIN 3 is not very high, waiting for the results of biopsies done during a colposcopy is often the first step.

In some cases, expedited treatment (treatment without doing biopsies) is recommended. This approach is recommended for non-pregnant women over the age of 25 when the risk of CIN 3 is considered to be 60% or more, and is an acceptable approach if the risk if between 25% and 60%.

Examples include women who have a Pap smear result that shows HSIL along with an HPV test that is positive for HPV 16. This is also the case in women who have a positive HPV test for any strain of HPV, and have not had recent cervical cancer screening.

Removing tissue in this case not only removes the abnormal tissue, but may reduce the possibility of cervical cancer in the future.

Treatment During Pregnancy

Some of the treatments used for HSIL cannot be used during pregnancy. Your healthcare provider will help you understand whether you need to have an immediate colposcopy or if you can wait until you are postpartum (at least four weeks). If you had biopsies showing CIN 2 or CIN 3, they may recommend holding off on treatment and simply testing (Pap or colposcopy) every 12 weeks, but this will vary depending on your particular risk factors.

Young Patients

Treatment choices need to be individualized in women under the age of 25. With younger women there is a higher chance of regression (cervical changes going away on their own), and any treatment is more likely to impact future pregnancies. That said, biopsies that are returned as CIN 3 should always be treated, as they are considered direct precursors to cancer.

Treatment Methods

There are advantages and disadvantages with all methods used to treat HSIL, and your healthcare provider will help you weigh the benefits (the chance that the procedure will be effective in removing abnormal tissue), against the risks (the chance of side effects related to the procedure).

Treatments can be broken down into those that are excisional (remove tissue) and those that are ablative (destroy tissue). Depending on your situation, one of these approaches may be preferred.

Excisional treatments for HSIL include:

  • Loop Electrosurgical Excision Procedure (LEEP): During a LEEP, an electric current is sent through a wire loop. The wire loops act as a knife, removing abnormal cervical cells.
  • Conization: Also called a cone biopsy or cold knife ionization, conization removes a larger, cone-shaped sample of abnormal tissue.
  • Laser cone biopsy: This type of laser therapy uses a tiny beam of light to cut out abnormal cells.

Ablative treatments for HSIL include:

  • Cryotherapy: Cryotherapy is a technique that's used to destroy abnormal tissue by freezing it. It is also called cryosurgery.
  • Thermal ablation: Thermal ablation is similar to cryotherapy, but uses heat instead of cold to destroy tissue.
  • Laser ablation: This type of laser therapy uses a tiny beam of light to destroy abnormal cells.

Excisional treatments, such as LEEP or conization, are used more commonly in the United States and have the advantage of providing a piece of tissue that a pathologist can view under the microscope (to assess the margins, or how close any abnormal cells were to the edge of the sample), and helping to predict the risk of recurrence. While associated with a lower risk of recurrence, excisional techniques also tend to have a higher risk of adverse effects.

In some situations, excisional treatment should always be done. This includes abnormal changes that extend into the cervical canal and more.

The primary risk with excision methods is of pregnancy complications, such as premature births, in the future. Since abnormal cervical changes alone may increase the risk of preterm births, your healthcare provider will help you understand the best option for you if you plan to become pregnant in the future.

Follow-Up Care After Treatment

Following up after treatment for HSIL is absolutely necessary. Cells can become abnormal again, despite treatment, and may require additional treatment.

Follow-up care consists of regular Pap smears and colposcopy exams for an extended period of time. Your particular schedule of follow up will depend on results of any biopsies you had and treatments you have chosen, but is usually at least annually for a few years.

Since the risk of abnormalities progressing to cancer lasts for at least 25 years, it's recommended that after treatment and the initial first years of followup, testing (either HPV or cotesting) should be continued for at least 25 years, or at least as long as life expectancy warrants testing and that testing does not compromise health.

A Word From Verywell

If you are feeling anxious after being told that you have an abnormal Pap smear, especially one that shows high-grade changes, keep in mind that cervical cancer is one of the more easily prevented cancers and it is a slow-progressing disease that often takes years to develop.

While it can be frustrating to undergo treatments and so many follow-up appointments, you are taking steps to prevent cervical cancer or to detect it at an early stage when treatment is more likely to be successful.

Cervical Cancer Healthcare Provider Discussion Guide

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6 Sources
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  2. Massad LS, Einstein MH, Huh WK, et al. 2012 updated consensus guidelines for the management of abnormal cervical cancer screening tests and cancer precursors. J Low Genit Tract Dis. 2013;17(5 Suppl 1):S1-S27. doi:10.1097/LGT.0b013e318287d329

  3. Centers for Disease Control and Prevention. Cervical cancer is preventable.

  4. 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

  5. National Cancer Institute. Dictionary of cancer terms: CIN.

  6. American Cancer Society. Survival rates for cervical cancer.