What is High-Grade Squamous Intraepithelial Lesion of the Cervix?
High-grade squamous intraepithelial lesion (HSIL) is a type of abnormal cell change linked to the human papillomavirus (HPV). It could potentially become cancerous if not treated, although it’s not guaranteed. In the past, it was referred to under various labels, including cervical intraepithelial neoplasia grades 2 and 3 (CIN 2 and CIN 3), moderate and severe dysplasia, and carcinoma in situ. However, in 1988, the Bethesda System for Reporting Cervical Cytology suggested a new name for this condition—HSIL. This title was later endorsed by the Lower Anogenital Squamous Terminology Standardization Consensus Conference (LAST) and the World Health Organization (WHO) in 2012 and 2014, respectively.
Even though not every case of HSIL becomes cancer, it’s viewed as a step before cancer and is thus typically treated in a serious, aggressive manner. Although HSIL can appear in various skin and mucus-producing areas within the genital and anal area, in this context, we are specifically talking about HSIL that affects the cervix.
What Causes High-Grade Squamous Intraepithelial Lesion of the Cervix?
Research has shown that Human Papillomavirus (HPV) is the main cause of cervical cell abnormalities and cancer. HPV is a type of virus that doesn’t have an outer layer, and its genetic material is made of double-stranded DNA. This virus is part of the Papillomaviridae family, which includes over 150 different types of HPV. Around 40 of these types can affect the private parts.
Out of those 40, some are considered “high-risk” and others “low-risk”, depending on how likely they are to cause cancer. Two types, HPV 16 and HPV 18, pose a high risk and are found in more than 70% of severe cell abnormalities and cervical squamous cell cancers. This contrasts with low-grade cell abnormalities, which usually indicate a short-lived HPV infection that the body can clear within 2 to 5 years and that rarely turn into cancer.
However, severe cell abnormalities are often linked to long-lasting infections and carry a higher risk of developing into cancer, especially when the infection is caused by high-risk types like HPV 16 or HPV 18.
Risk Factors and Frequency for High-Grade Squamous Intraepithelial Lesion of the Cervix
HSIL, a condition caused by HPV infection, is often found in women with certain genetic and behavioral factors that make them more likely to get HPV. HPV is most common in young, sexually active women, and its prevalence tends to decrease until menopause, after which some studies show a slight uptick. This decrease in middle age is believed to be due to the immune system effectively fighting off the HPV after exposure, and less likelihood of being exposed to HPV. Those with weakened immune systems, such as people who have had transplants or are HIV-positive, are at a higher risk of having a persistent HPV infection, which can lead to the development of squamous intraepithelial lesion (SIL).
- Starting to be sexually active at a younger age and having more sexual partners can increase the risk of HPV infection.
- The promiscuity of a male partner also plays a part.
- Using condoms and circumcision can reduce the risk of HPV infection.
- There is no difference in HPV prevalence based on sexual orientation.
- Women who have given birth many times, especially those who have had more than seven births, are at an increased risk.
Smoking has a strong connection to cervical neoplasia, regardless of whether or not the person has HPV. This is likely due to the presence of cancer-causing substances in cervical mucus. Certain HLA class II alleles and haplotypes – notably, HLA DRB1*07 and HLA-DQB1*03 – have been found to be positively associated with SILs and invasive cancer. These genetic variations might affect how HPV antigens are presented and the immune response to them. Conversely, other HLA class II haplotypes can be protective. The use of oral contraceptives might slightly increase the risk of cervical neoplasia, but the overall increase in absolute risk is minimal.
Signs and Symptoms of High-Grade Squamous Intraepithelial Lesion of the Cervix
Women who have been diagnosed with HSIL (high-grade squamous intraepithelial lesions) through a biopsy are likely to have several risk factors for HPV (human papillomavirus) infection. They may have tested positive for HPV and/or have a history of abnormal Pap smear tests. When examined using colposcopy, a method for visualizing the cervix, certain features suggest high-grade changes. These include:
- Dense white patches on the cervix (acetowhite epithelium)
- Rapid reappearing of white patches after being wiped off (rapid appearance of acetowhitening)
- Visible crypt openings surrounded by a white ring (cuffed crypt openings)
- Appearance of a network of white lines (coarse mosaicism)
- Appearance of white dots (coarse punctuation)
- A sharp, clear boundary between normal and abnormal areas (sharp border)
- A clear white patch within a lighter white area (inner border sign)
- The presence of thick, irregular white patches at the junction between the ectocervix and endocervix (ridge sign)
Testing for High-Grade Squamous Intraepithelial Lesion of the Cervix
A Papanicolaou (Pap) test is a common way to screen for early signs of cervical cancer. It’s done by opening the vagina with a tool called a speculum to clearly see the cervix. Cells are then collected from the cervix using a special brush or spatula, and then preserved in a liquid or placed directly onto a microscope slide. The collected cells are then sent to a laboratory for examination.
The American College of Obstetricians and Gynecologists (ACOG) recommends that women begin receiving Pap tests at 21 years of age. If you’re between the ages of 21 and 29, you should have a Pap test every three years. From ages 30 to 65, you should have a Pap test plus an HPV (human papillomavirus) test every five years or just a Pap test every three years. HPV is a common sexually transmitted infection that can sometimes cause cervical cancer. The HPV test looks for high-risk subtypes of the virus, including ones known as HPV 16 and 18.
If you have a Pap test that shows abnormal cells and you’re also positive for HPV, your healthcare provider will follow guidelines created by the American Society for Colposcopy and Cervical Pathology (ASCCP) for next steps. If you’re between 21 and 24 and have a diagnosis of High-grade squamous intraepithelial lesion (HSIL) from your Pap test, which is a condition that may lead to cervical cancer, the ASCCP recommends a procedure called a colposcopy. This is a closer examination of your cervix using a special microscope. If you’re over 24, a colposcopy is usually also recommended, but sometimes a different procedure might be used.
During a colposcopy, a biopsy or small sample of tissue may be taken for further examination. About 60% of women with HSIL will be diagnosed with a condition known as CIN 2, which is a moderate to high-grade change in the cervix that could become cancerous. Around 2% will be diagnosed with invasive cancer, although this is more common in older women. If you’re over 30 and your Pap test shows HSIL, you have about an 8% risk of developing cervical cancer in the next five years.
Even after successful treatment of significant cervical changes or early-stage cancer, you should continue to have regular screenings for at least 20 years. This is true even if you’re over 65, which is typically the age at which cervical screening might otherwise stop.
Treatment Options for High-Grade Squamous Intraepithelial Lesion of the Cervix
For women between the ages of 21 and 24 who have HSIL cytology – which is a type of test that checks for abnormal cells – medical professionals recommend a procedure called colposcopy. This procedure examines the cervix, vagina and vulva for signs of disease. If an abnormal tissue known as CIN 2 or higher isn’t found on biopsy, it is suggested that these patients have a follow-up with cytology and colposcopy tests every 6 months for two years, as long as the exams are showing no, or only very minor, abnormalities. If a high-grade abnormality is found during this period, a biopsy should be carried out. If persistent abnormalities are called HSIL cytology, but no high-grade lesion is found after two years, a diagnostic excisional procedure is recommended. This procedure involves removing a part of the tissue for study.
However, if the colposcopy procedure can’t fully check the cervix, a diagnostic excisional procedure is recommended. If the patient’s biopsy identifies CIN 2, it should be monitored for a year with both cytology and colposcopy tests every 6 months. These guidelines exist since CIN 2, especially in younger women, is more likely to resolve itself and has a lesser risk of developing into cancer than CIN 3. After the patient gets two consecutive negative results on tests without evidence of abnormalities, they are advised to have a ‘co-test’ a year later. If the results are normal for a second ‘co-test’ after three years, the patient is considered clear. If either co-test shows an issue, colposcopy is recommended again.
For women aged 25 or above, the preferred course of action with a HSIL Pap test result is an expedited treatment if the immediate risk of CIN 3+ is 60% or more and is acceptable if the risk is between 25% and 60%. Expedited treatment refers to treatment without an earlier colposcopic biopsy. In women with HSIL and positive testing for HPV 16, an infection caused by the human papillomavirus, expedited treatment is preferred. Future pregnancy risks and shared decision-making should be considered when discussing quick treatment.
For women with HSIL, if the colposcopy does not provide enough information, a diagnostic excisional procedure is advised. If the procedure is adequate and confirms HSIL on biopsy, then removal or destruction of the transformation zone (the cervical area most likely to develop cervical cancer) is considered acceptable. However, in cases where colposcopy is inadequate or if a tissue sample from the canal of the cervix shows a high-grade lesion, then a diagnostic excisional procedure is acceptable.
Post-treatment, regardless of age, the suggestion is for HPV co-testing (which tests for presence of risky strains of HPV along with cell abnormalities) at 12 and 24 months after treatment. If both tests come back negative, the patient can be retested after 3 years. If this test is negative too, the patient can then return to normal screening for at least the next 20 years. However, an abnormal test result will necessitate a colposcopy with endocervical sampling – taking a tissue sample from the canal of the cervix.
Expectant women with HSIL cytology should avoid excisional treatment. In this situation, only a colposcopy is recommended. If a biopsy confirms a high-grade lesion, the patient may have additional colposcopies every 12 weeks. If test results suggest invasive cancer, or if the appearance of the lesion worsens, then a biopsy is recommended. It’s often considered acceptable to delay further evaluation until at least 6 weeks after childbirth.
What else can High-Grade Squamous Intraepithelial Lesion of the Cervix be?
There are several medical conditions which may resemble high-grade squamous intraepithelial lesion (HSIL) when viewed under a microscope. These include:
- Early stage cervical cancer
- Atrophy (shrinkage of tissues)
- Squamous metaplasia (change in cell type)
- Transitional metaplasia (another form of cell change)
- Reactive atypia (abnormal cells in response to inflammation or irritation).
What to expect with High-Grade Squamous Intraepithelial Lesion of the Cervix
High-grade squamous intraepithelial lesions (HSILs) are linked with continuous human papillomavirus (HPV) infection. This puts a person at a higher risk of developing invasive cancer, particularly if the persistent infection is of a high-risk type like HPV 16 or HPV 18.
Preventing High-Grade Squamous Intraepithelial Lesion of the Cervix
Teaching patients about the risk factors of HPV exposure and safe sexual practices can help lower the chance of getting HPV. They should understand how a person gets exposed to HPV and how to effectively reduce this risk.
Vaccines are available that can protect against the high-risk types of HPV (types 16 and 18) and the low-risk types (types 6 and 11). They are very effective at preventing people from initially getting HPV and can even stop the virus from staying in the body. These vaccines also help the body fight against harmful changes in the cells (squamous intraepithelial lesions) that HPV can sometimes cause.
Most serious changes are linked to HPV type 16, so it’s expected that the vaccine can reduce the chance of these serious changes by up to 87%. However, this is still being studied in the general public.
It’s also very important to talk about the risks and benefits of treating serious HPV lesions. Patients should understand how this treatment may affect future pregnancies. This explanation can help them make informed decisions about their health.
