Vulval intra-epithelial neoplasia (VIN)
Vulval intra-epithelial neoplasia (VIN) is a skin condition that can affect the vulva and, in some women, may develop into cancer after many years.
We hope this information answers your questions. If you have any more questions, you can ask your doctor or nurse at the hospital where you are having your treatment.
The vulva is a woman's external genital area. It includes two large, hair-covered folds of skin called the labia majora, which surround two thin and delicate folds called the labia minora. The labia majora and labia minora surround the opening of the vagina and the tube through which urine is passed (the urethra).
The clitoris is positioned above the vagina and urethra. This small structure is very sensitive and helps a woman reach sexual climax (orgasm). The opening to the back passage (anus) is separated from the vulva by an area of skin called the perineum.
Vulval intra-epithelial neoplasia (VIN)
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The term VIN refers to particular changes that can occur in the skin that covers the vulva. VIN is not cancer, and in some women it disappears without treatment.
If the changes become more severe, there is a chance that cancer might develop after many years, and so VIN is referred to as a pre-cancerous condition.
Although VIN used to be quite rare, it's now being recognised and diagnosed more frequently. It can affect women of any age from their 20s onwards.
VIN is divided into two main types depending on its characteristics.
Usual type VIN
Nearly all VIN is usual type VIN. This type is more common in younger women aged 35–55 and is associated with HPV (human papilloma virus – see below). Usual type VIN can be further divided into: VIN, warty type; VIN, basaloid type; and VIN, mixed (warty, basaloid) type.
Differentiated type VIN
This type is much rarer and is more common in older women aged 55–85. It can often occur alongside other skin conditions that can affect the vulva, such as lichen sclerosis.
Previously (before 2004) VIN was classified as grade I, 2 or 3, depending on how the cells looked under the microscope. However, the new classification (usual type and differentiated type) is now more widely used.
Usual type VIN is associated with an infection in the skin of the vulva by a virus known as human papilloma virus (HPV).
HPV is a very common infection. There are over 100 types of the virus and each type is known by a number. The most common types (known as low-risk HPV) can cause warts on the skin of the hands or verrucas on the feet. Other types can cause cell changes in the genital area, including the cervix, vulva and anus. These types of HPV are known as high-risk HPV and some of them may cause VIN. The types most commonly associated with VIN are 16, 18 and 31.
Genital HPV infection is spread by direct skin-to-skin contact during sex with someone who has the infection. HPV is so common that most sexually active women will be exposed to it at some time in their life. In most women, their body's own immune system will get rid of the HPV naturally, without them ever knowing it was there.
Not all women who have HPV will develop VIN. Differentiated type VIN is not associated with an HPV infection.
Other factors that depress the body's immune system can also increase the risk of VIN. These include smoking, particular medicines (such as those taken after transplant surgery), inherited immunity problems and some rare bone marrow and blood disorders.
Signs and symptoms of VIN
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The signs and symptoms vary, and may include some, or all, of the following:
itching and soreness in the vulva
burning, or a severe tingling sensation, that can become worse when passing urine
one or more areas of reddened, white or discoloured skin in the vulva
raised areas of skin that can vary in size
the skin having a warty appearance
pain during sex.
Rarely, no symptoms are apparent, and some women are diagnosed with VIN while having medical tests for other health problems. If you do have any of the symptoms mentioned here, let your doctor know. These symptoms can be caused by conditions other than VIN but it’s best to get them checked. Your doctor can examine you and, if necessary, refer you to a doctor who specialises in women's health (a gynaecologist).
Your doctor will examine your vulva and may use a special microscope (a colposcope), which magnifies the area so that any changes can be clearly seen. They will then take a small sample of cells from the affected area (biopsy) to examine under a microscope. Before a biopsy is taken, a local anaesthetic cream is usually used to numb the area. This usually takes around 20 minutes to work. Liquid anaesthetic is then injected into the area using a small needle. Sometimes a general anaesthetic may be given. A sample of cells is then taken from the vulva.
The doctor will also examine your cervix and vaginal walls to look for any abnormalities in the cells.
VIN is not cancer, but it causes changes to the cells of the vulva. If the cell changes are mild, treatment may not be needed, but your doctors may suggest that you have the area checked regularly.
Treatment may be needed for some women. The type of treatment most appropriate for you will depend on:
the size of the affected area
the estimated risk of the area developing into cancer.
If you smoke, giving up can help strengthen your immunity, make the treatment more effective and reduce the chance of the VIN coming back after treatment.
In certain situations, it may be possible to delay treatment for a period of time (for example, if you're pregnant). In this situation the VIN would be closely monitored for any changes.
In women who need treatment, most will have the affected area removed with surgery known as local surgical excision. Rarely, if the affected area is large or there are several areas, the whole vulva may be removed in a vulvectomy. Sometimes the vulval tissue can be replaced with skin taken from another part of the body (a skin graft). We have more information about this in our section on cancer of the vulva.
Ablation means destroying the affected area. It may be used for areas where it's difficult to surgically remove the VIN, such as around the clitoris. Ablation can be done using a high-energy beam (laser) or a tiny electrical current passed through a probe (diathermy).
The laser beam or diathermy is focused on the affected areas to destroy the abnormal cells.
Before any treatment, it's important that you know exactly how much skin is going to be removed and how this will affect you afterwards. Your specialist can discuss this with you before you have the treatment.
New treatments that are being researched
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The following treatments (imiquimod, cidofovir and photodynamic therapy) are experimental and are being investigated in research trials to see how useful they might be for VIN.
Imiquimod is medicine that comes as a cream that you apply to the affected area (your doctor will prescribe how often and for how long). It is a type of drug known as an antiviral drug. The idea is that it stimulates the immune system to get rid of the HPV infection, which in turn will allow the vulva cells to return to normal. The main side effect of this treatment is inflammation of the affected area.
Research is also looking into another antiviral drug treatment for VIN called cidofovir, but this is at an early stage.
Photodynamic therapy (PDT)
PDT uses laser light to activate a light sensitive drug. The drug is given either as a cream that is applied to the vulva or as an injection into a vein (intravenously). A laser light is then shone onto the affected area which activates the drug to destroy the abnormal cells. More research is needed to find out how useful PDT might be in treating VIN.
Creams to relieve symptoms
Steroid cream can be applied to the affected areas. It reduces inflammation and can control symptoms, but doesn't cure the condition.
Sometimes a local anaesthetic cream/gel can be used to ease any soreness or discomfort.
There is a risk that VIN can come back after treatment, so you will be seen regularly by your specialist, often for many years. Your doctors will check for signs of any further changes that may need to be treated. If there is only a small chance of your VIN returning, your specialist may discharge you into the care of your GP.
If you notice any new symptoms or changes, it's important to let your GP know so that you can be referred back to your hospital specialist.
Many women feel frightened when they are first told they have VIN and worry that they may develop cancer. You may find the treatments both embarrassing and upsetting, and may feel tense, tearful or withdrawn. At times, these feelings can be overwhelming and hard to deal with.
You may have many different emotions including anger, resentment, guilt, anxiety and fear. These are all normal reactions, and are part of the process many people go through in trying to come to terms with their condition.
Everyone has their own way of coping with difficult situations. Some people find it helpful to talk to family or friends, while others prefer to seek help from people outside their situation. Some people prefer to keep their feelings to themselves. There is no right or wrong way to cope, but help is there if you need it. Our cancer support specialists
can give you information about counselling in your area.
Vulval Pain Society
Vulval Pain Society is a voluntary organisation run by a doctor and nurse that gives information and support to women with any vulval condition.
This fact sheet has been compiled using information from a number of reliable sources, including:
Dynamed. Summary: Vulval intraepithelial neoplasia. Updated October 2011(accessed Oct 2012).
Holschneider C. Vulvar intraepithelial neoplasia. September 2012 (accessed Oct 2012).
Kaushik S , et al. Surgical interventions for high-grade vulval intraepithelial neoplasia. January 2012. Cochrane Library Online (accessed Oct 2012).
Pepas L, et al. Medical interventions for high-grade vulval intraepithelial neoplasia. April 2011. Cochrane Library Online. (accessed Oct 2012).
With thanks to Professor David Luesley, Professor of Gynaecological Oncology, and the people affected by cancer who reviewed this edition.
Reviewing information is just one of the ways you could help when you join our Cancer Voices network.