High Grade Squamous Intraepithelial Lesion (HSIL)

What It Means and What Happens After the Diagnosis

Table of Contents
View All
Table of Contents

An abnormal Pap smear result of high-grade squamous intraepithelial lesion (HSIL) means that an area of cells of the cervix (the narrow neck of the uterus) looks abnormal when examined under a microscope.

HSIL is caused by chronic infection with certain types of human papillomavirus (HPV). HSIL is also called moderate or severe dysplasia or cervical intraepithelial neoplasia (CIN 2 or CIN 3). Treatment may include monitoring for changes in cells or an outpatient procedure, such as ablation (destroying the cells) or surgery to remove the cells.

This article provides an overview of HSIL. It covers what it is, how it is treated, and what follow-up care entails.

Pap smear medical test
JodiJacobson / Getty Images

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

What Does It Mean to Have HSIL?

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

If there are early changes in the size and shape of the cells it is considered low-grade squamous intraepithelial lesion (LSIL), also called mild dysplasia or CIN 1.

With HSIL, the cells appear very different from normal cells. These precancerous lesions are more severe than with LSIL and may also be called moderate or severe dysplasia, or CIN 2 or 3.

Is HSIL Cancer?

HSIL is not cancer, but it is more likely to become cervical cancer than LSIL. Many of these lesions will regress on their own, but CIN 3 is the most advanced form of HSIL and the one most likely to progress to cancer.

What Happens After a HSIL Diagnosis?

With HSIL, it is not known whether there are precancerous or cancerous changes happening. So additional testing after the Pap test is necessary to see what is happening to the cervical cells.

Additional testing of the cervical cells is typically needed to confirm cervical dysplasia and to learn more about the severity of the abnormal cells.

Treating HSIL can help prevent precancerous and cancerous changes. HSIL may be treated first with monitoring to see if it persists or with an outpatient procedure in the healthcare provider's office.

When choosing the best treatment for an HSIL Pap smear result, healthcare providers look at:

  • Your overall health and medical history
  • Extent of the lesion
  • Your tolerance for specific medications, procedures, or therapies
  • Expectations for the course of the lesion
  • Whether you plan to become pregnant in the future or are currently pregnant
  • Your opinion or preference

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

Expedited Treatment

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

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

Examples include individuals with a Pap smear result that shows HSIL and an HPV test that is positive for HPV 16. This is also the case in those with a positive HPV test for any strain of HPV and who 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 might recommend holding off on treatment and simply testing (Pap or colposcopy) every 12 weeks, but this will vary depending on your particular risk factors.

Younger People

Treatment choices need to be individualized in people under the age of 25. This is because younger people have 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 returned as CIN 3 should always be treated, as they are considered direct precursors to cancer.

HSIL Treatments

There are advantages and disadvantages to all methods used to treat HSIL, and your healthcare provider will help you weigh the benefits against the risks.

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.

Ablation

Ablation treats abnormal cells by using things like freezing, heat, or other measures to destroy the cells. There are different kinds of ablative treatments.

Cryotherapy: a technique that's used to destroy abnormal tissue by freezing it. It is also called cryosurgery.

CO2 Laser Ablation: This type of laser therapy uses a tiny beam of light to destroy abnormal cells.

Thermal ablation: This is similar to cryotherapy but uses heat instead of cold to destroy tissue.

Surgical Excision

Surgical excision removes the abnormal tissue to treat it. Excisional treatments 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), 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.

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.

Laser Cone Biopsy: This type of laser therapy uses a tiny beam of light to cut out abnormal cells.

Cold Knife Cone: Also called a cone biopsy or cold knife ionization, conization removes a larger, cone-shaped sample of abnormal tissue.

Topical Therapy

Right now there are no topical therapies approved to treat HSIL, but there are some being studied.

Imiquimod Cream: One study found 61% of participants receiving treatment with imiquimod cream applied to the cervix weekly had regression of their HSIL. There were various adverse effects, like itching, vaginal ulcer, and pelvic pain. More studies are needed to evaluate this treatment.

Cidofovir Cream: This antiviral cream is a treatment for vulvar and non-genital HPV lesions, as well as for viruses like herpes. Studies of the cidofovir gel being used in a variety of dosing schedules have shown effectiveness for treating HSIL, with regression of the disease. More studies need to be done.

5-Flurorouracil (5-FU) Cream: This is an antimetabolite drug—prevents cancer cells from making more cancer cells—that is also used as a chemotherapy drug. Topical 5-FU has been used to treat genital warts and vulvar/vaginal dysplasia.

It cannot be used daily because of adverse effects, so it's been limited to biweekly dosing or diluting the strength of the topical solution. It has shown some effectiveness in treating HSIL, but more studies are needed to evaluate its safety and effectiveness.

Follow-Up Care After Treatment

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

Follow-up care consists of regular Pap smears and colposcopy exams for an extended period. Your follow-up schedule will depend on the results of any biopsies you had and treatments you have chosen, but it 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 first years of follow-up, testing (either HPV or co-testing) should be continued for at least 25 years. Testing should not compromise your health.

Summary

Regular pap smear exams screen for any abnormal changes to the cervix. When HSIL is diagnosed, further testing is necessary along with an evaluation of your overall health and plans for future pregnancies. This can help determine the best treatment options for you.

Your healthcare provider will go over your treatment options and what to expect with your course of treatment and follow-up. Treatment is necessary because left untreated, HSIL is more likely to lead to precancer or cancer of the cervix.

A Word From Verywell

If you feel 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. 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 detect it early when treatment is more likely to be successful.

Cervical Cancer Healthcare Provider Discussion Guide

Get our printable guide for your next healthcare provider's appointment to help you ask the right questions.

Doctor Discussion Guide Woman
7 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. National Cancer Institute. NCI dictionary of cancer terms: HSIL.

  2. Johns Hopkins Medicine. Cervical dysplasia.

  3. Goodman A. Patient education: Follow-up of high-grade or glandular cell abnormal Pap tests (Beyond the basics). UpToDate.

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

  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. Fonseca BO, Possati-Resende JC, Salcedo MP, et al. Topical imiquimod for the treatment of high-grade squamous intraepithelial lesions of the cervix: a randomized controlled trial. Obstet Gynecol. 2021;137(6):1043-1053. doi:10.1097/AOG.0000000000004384

  7. Desravines N, Miele K, Carlson R, Chibwesha C, Rahangdale L. Topical therapies for the treatment of cervical intraepithelial neoplasia (CIN) 2-3: a narrative review. Gynecologic Oncology Reports. 2020;33. doi:10.1016/j.gore.2020.100608

Jaime R. Herndon

By Jaime R. Herndon, MS, MPH
Jaime Herndon is a freelance health/medical writer with over a decade of experience writing for the public.

Originally written by Lisa Fayed