What is Vulvar Intraepithelial Neoplasia?
Vulvar intraepithelial neoplasia (VIN) is a condition where abnormal cells are found on the surface of the vulva, but haven’t yet turned into cancer. It’s important to know, though, that this condition can eventually lead to vulvar squamous cell carcinoma, a type of skin cancer that affects the vulva. This condition can’t be detected through routine testing, which means doctors need to carefully examine any unusual changes to the vulva and conduct a biopsy, where a little piece of the affected skin is removed and examined under a microscope.
The VIN condition can present as bumps, flat areas, or colored regions that may be white, gray, or otherwise discolored. All these descriptions refer to its physical appearance and identifying them is important for an accurate diagnosis. However, to confirm the condition, a biopsy, as mentioned earlier, is necessary.
In 2015, an organization called the International Society for the Study of Vulvovaginal Disease (ISSVD) proposed a new way to classify these so-called “vulvar squamous intraepithelial lesions” or SILs, which are essentially the VIN conditions. Their proposed classifications included:
- Low-grade SIL (LSIL) of the vulva – which can also be referred to as flat condyloma or a sign of human papillomavirus (HPV) infection. This used to be called VIN 1.
- High-grade SIL (HSIL) of the vulva – which can also be referred to as vulvar HSIL, or the usual type of VIN or uVIN. This was previously known as VIN 2 and VIN 3.
- Different VIN (dVIN), which was previously known as the simplex type of VIN.
What Causes Vulvar Intraepithelial Neoplasia?
Vulvar intraepithelial neoplasia, or VIN, is a condition that has two different types: uVIN, which is usually caused by the HPV virus, and dVIN, which is typically linked to long-lasting inflammation. The way we classify these types of VIN is based on their histology, which is basically the study of the microscopic structure of tissues. There’s no need for HPV testing to figure out which type it is.
dVIN makes up a small portion (about 5%) of all VIN cases, but it’s associated with a higher chance of advancing to a form of skin cancer known as squamous cell carcinoma (SCC).
On the other hand, uVIN is related to the HPV virus. Having this type can increase the risk of developing other cancers in the area around the anus or genitals.
Keep in mind that low-grade lesions (small areas of abnormal tissue) are not seen as precancerous and are treated like condyloma, a type of genital wart. It’s noteworthy that most cases of VIN show presence of the HPV virus, ranging from 72% to 100%. The HPV-16 strain is the most common type found in these cases.
Risk Factors and Frequency for Vulvar Intraepithelial Neoplasia
Vulvar intraepithelial neoplasia (VIN), a disease affecting women, is more common in White women than non-White women. The most cases are reported in women in their 40s. There are two main types of VIN. The undifferentiated type (uVIN) often affects younger women, even adolescent girls, with the average age of these patients being 40 years old. The differentiated type (dVIN) is usually found in older women, with an average age of 60 years at presentation.
VIN is most often associated with the human papillomavirus (HPV). The three most common types of HPV found in VIN are types 16, 18, and 33. Apart from HPV, other risk factors for VIN include having multiple sexual partners, smoking cigarettes, and having weak immune systems due to conditions such as HIV, autoimmune diseases, or organ transplants. Specific skin conditions, such as lichen sclerosis, are risk factors for dVIN.
A recent study of 1,100 patients revealed that both high-grade VIN and dVIN rates are on the rise. This could be due to increased awareness of VIN, resulting in more biopsies of the vulva. Additionally, the chance of developing cancer of the vulva is significantly higher in patients with dVIN than with high-grade VIN. In some studies, the risk of vulvar cancer in women with dVIN was between 33% and 86%, with the disease progressing in as little as 9 to 23 months.
- uVIN often affects younger women and is largely related to HPV, specifically types 16, 18, and 33.
- On the other hand, dVIN generally affects older patients and is more related to skin conditions.
- The risk of developing cancer is up to 20% for those with uVIN and up to 80% for those with dVIN.
- In terms of immunohistochemistry, uVIN typically tests negative for p53 but positive for p16. In contrast, dVIN usually tests positive for p53 and negative for p16.
Signs and Symptoms of Vulvar Intraepithelial Neoplasia
Vulvar intraepithelial neoplasia (VIN) is a condition that is diagnosed clinically, meaning it is based on medical examination rather than a routine screening test. Usually, if any irregularities are picked up in tests associated with cervical cancer screening, such as abnormal cell changes or a positive high-risk HPV test, a separate examination of the vulva will be required.
It’s important to remember that using acetic acid alone is not a reliable method for diagnosing VIN. This is because the whitened color it could cause on any detected lesions doesn’t exclusively indicate vulvar intraepithelial neoplasia.
When a doctor examines the vulva for the presence of lesions, certain characteristics are noted. These include:
- Location of lesions
- Number of lesions
- Size of lesions
- Shape of lesions
- Color of lesions
- Thickness of lesions
VIN is usually multifocal, meaning it occurs in several areas. The lesions can appear in various ways. They might be raised, bumpy and white, or alternatively, they could be red, gray, or even pigmented. Given that no single appearance is definite for VIN, taking a biopsy of any abnormal vulvar spot is necessary. Also, it’s not uncommon for different patterns to be seen in the same patient.
Testing for Vulvar Intraepithelial Neoplasia
uVIN and dVIN are two different types of vulvar intraepithelial neoplasia (VIN), a precancerous condition in women’s intimate area. uVIN often appears in multiple spots and is raised. It’s usually found around the entrance to the vagina (the introitus) and the outer part of the female genitals (the labia majora). dVIN, on the other hand, appears as poorly outlined pink or white spots. These spots are often seen in conjunction with lichen sclerosis or lichen planus, two common skin conditions. Unlike uVIN, dVIN is difficult to treat with medicine alone.
Your doctor can do a special examination called a colposcopy to get a better look at your vulva, the external part of your female genitalia. This involves using a device that can magnify the area. They might also use a simple magnifying lens. However, a test that involves using a toluidine solution, known as the Collins test, is not usually recommended. This is because it is not very specific and might give inaccurate results.
When examining your vulva, your doctor will check all parts – the labia majora and minora (the larger and smaller ‘lips’), the vestibule (the area around the opening of the vagina), the clitoris, and the urethra (where urine comes out), as well as the perineum (the area between the vagina and anus) and the perianal area (around the anus). If they find any high-grade (severe) lesions, or abnormal areas, they might also need to examine the anal canal and take a sample of cells (a cytology test). This is because up to 18% of women with high-grade changes in the vulvar cells may also have similar changes in the anal area. If your doctor sees any lesions on your vulva, they will take a biopsy, where a small sample of tissue is removed for examination. This will help them decide on the best treatment for you.
Treatment Options for Vulvar Intraepithelial Neoplasia
The ideal treatment for Vulvar Intraepithelial Neoplasia (VIN), a precancerous skin condition that affects the vulva, aims to completely remove the affected area, improve symptoms, and preserve the function of the vulva. Treatments can be surgical or medical, or it may involve observation and regular check-ups. Prevention of the disease through vaccination can also significantly reduce its impact.
For usual VIN (uVIN), cold knife surgery and loop electrosurgical excision procedure (LEEP) are generally preferred. These treatments involve removing the affected skin. However, there is also an alternative treatment, CO2 laser ablation, which uses a laser to destroy the diseased tissue. While this method helps preserve normal anatomy and minimizes scarring, it does slightly increase the risk of recurrence.
Medications can also be used for treating uVIN. Imiquimod is a medication that stimulates the immune system and can fight both viruses and tumors. Research has shown that this drug can be as effective as surgery in certain cases. It may cause local irritation, redness, and erosions. Other less commonly used treatments are Cidofovir, an antiviral medication that promotes the death of virus-infected cells, and photodynamic therapy, which uses light to destroy cells.
In the case of differentiated VIN (dVIN), which is often linked with skin conditions like lichen sclerosis and skin cancer specifically Squamous Cell Carcinoma (SCC) of the vulva, the treatment often involves surgical excision using a scalpel, LEEP, or laser. This type of VIN has a higher recurrence rate, hence wide local surgery is generally the first choice for treatment.
Observation and close surveillance can also be an effective approach for managing uVIN. Spontaneous regression, where the condition clears up on its own, has been reported in uVIN. However, it is more likely in younger patients (under 35 years of age) and can be influenced by factors like the patient’s age, immune system health, and how much of the vulva is affected. Regardless of regression, these patients should be closely monitored. Pregnancy can affect the progression of precancerous vulvar lesions, causing both an increased rate of spontaneous regression and progression.
Preventing VIN can be achieved through Human Papillomavirus (HPV) vaccination, which has considerably reduced the occurrence of VIN in young women. However, this vaccine is preventative and should not be considered a treatment for existing lesions.
What else can Vulvar Intraepithelial Neoplasia be?
If you have a visible lesion or abnormal growth in the vulva area, it’s important to get a biopsy. This is a test where a small sample of tissue is taken to check for any problems. Different types of skin changes or issues can cause these lesions.
Some of these problems can be benign, or not harmful. These can include conditions such as:
- Lichen simplex, lichen sclerosis, or lichen planus, which are common skin issues
- Vestibulitis, candidiasis, or herpes, which are infections
- Genital warts, psoriasis, condyloma acuminata, and seborrheic keratosis
Some of these lesions can look like VIN, a type of pre-cancerous lesion. They can also look similar to certain skin cancers like basal cell carcinoma, SCC, Paget disease, or melanoma. It’s really critical to get a biopsy to correctly identify these lesions. If you try to treat them without confirming what they are through a biopsy, you risk allowing the condition to progress undetected and you may also delay identifying a potential cancer.
What to expect with Vulvar Intraepithelial Neoplasia
If tested and treated early, biopsy-confirmed Vulvar Intraepithelial Neoplasia (VIN), a condition with potential to lead to vulvar cancer, has a positive outcome. The likelihood of it developing into invasive cancer is very low, unless the treatment is declined or significantly delayed. Without treatment, those with usual Vulvar Intraepithelial Neoplasia (uVIN) could see progression to invasive cancer in 6 to 7 years, while untreated differentiated Vulvar Intraepithelial Neoplasia (dVIN) could potentially lead to vulvar cancer in 2 to 4 years.
It’s important to have regular follow-ups after any treatment due to the high incidence of the condition reoccurring and the potential for late reoccurrences. Check-ups are advised every 6 to 12 months for at least five years for uVIN, and are required indefinitely for those with dVIN.
About a third to half of patients may face a reoccurrence of their condition, and 25% can experience late reoccurrences. There are several factors that increase the risk of reoccurrence, such as large lesion size, patients aged 50 years and older, positive excision margins (meaning there may still be some remaining disease after surgery), multifocal disease (disease affecting multiple areas), a weakened immune system, and tobacco use.
Possible Complications When Diagnosed with Vulvar Intraepithelial Neoplasia
The most serious problem arising from untreated vulvar intraepithelial neoplasia (VIN) is its progression to invasive cancer. When the disease becomes malignant, more extensive and serious surgery is needed. This type of surgery often leads to problems during and after the operation such as pain, infection, wound separation, and changes to the appearance of the vulva. The complications from the surgery depend on where the lesions were located, how many there were, and their size. On the other hand, topical treatments may cause irritation, a burning sensation, or the formation of skin ulcers.
Possible Side Effects:
- Progression to invasive cancer
- Pain
- Infection
- Wound separation (dehiscence)
- Changes to the appearance of the vulva
- Irritation from topical treatments
- Burning sensation from topical treatments
- Formation of skin ulcers from topical treatments
Preventing Vulvar Intraepithelial Neoplasia
For suitable individuals, the topic of receiving the HPV vaccine should be brought up to guard against diseases affecting the lower part of the genital tract. These diseases may include ‘condyloma’ and ‘uVIN’ (short for usual type Vulvar Intraepithelial Neoplasia). The HPV vaccine, especially the 9-valent type, has the potential to decrease the risk of acquiring uVIN by 80% to 90%. However, it’s important to note that getting the vaccine doesn’t lower the risk of developing ‘dVIN’ (differentiated Vulvar Intraepithelial Neoplasia).
Anyone who has had instances of genital warts or uVIN in the past should be advised to quit smoking. It’s also critical to inform patients about the importance of ongoing, lifelong check-ups. This is essential for catching potential issues early.
Proper and prompt treatment of skin conditions on the vulva, such as lichen sclerosis and lichen planus, can help lower the chances of getting dVIN or vulvar cancer. These conditions cause patches on the skin, especially in the genital area, that are itchy, painful, and may lead to changes in the skin’s color and texture.
