Vulval intra-epithelial neoplasia (VIN)

Vulval intra-epithelial neoplasia (VIN) refers to changes that can happen in the skin that covers the vulva. The vulva is the outer area of a woman’s genitals.

VIN is not cancer, and in some women it disappears without treatment. However it may develop into cancer after many years, so VIN is known as a pre-cancerous condition.

Symptoms of VIN can include itching, pain, tingling or burning in the vulva, changes to the way your skin looks around your vulva and pain during sex. See your doctor if you notice any of these signs. They will examine you and may need to do some tests to diagnose VIN. Not everyone has symptoms before they are diagnosed with VIN.

Your doctor may recommend you have surgery to remove the affected skin or use a procedure called ablation to destroy it. Drug treatments are also being developed. After treatment, you will see your doctor regularly to check that VIN hasn’t come back.

If you’re feeling concerned or worried about being diagnosed with VIN, help and support are available.

What is the vulva?

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 urine is passed through (the urethra).

The clitoris is 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.

The vulva
The vulva

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What is vulval intra-epithelial neoplasia?

Vulval intra-epithelial neoplasia (VIN) is a skin condition that can affect the vulva. In some women, this may develop into cancer after many years.

The term VIN refers to particular changes that can happen 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, 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 often. 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 the human papilloma virus – see below. Usual type VIN can be further divided into:

  • VIN, warty type
  • VIN, basaloid type
  • VIN, mixed (warty, basaloid) type.

Differentiated type VIN

This type is much rarer. It’s more common in older women aged 55–85. It can often occur together with other skin conditions that can affect the vulva, such as lichen sclerosis or lichen planus.

Causes of VIN

One of the most common causes of VIN is thought to be the human papilloma virus (HPV).

HPV is a very common infection. There are over 100 types, and each type is known by a number. Some types affect the genital area including the cervix, vagina and anus. Types 16, 18 and 31 are most commonly associated with VIN. In the UK all girls are now being vaccinated against types 16 and 18 at school.

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 are exposed to it at some time in their life. For most women, their immune system gets rid of the HPV naturally without them ever knowing they had the infection.

Not all women who have HPV will develop VIN. Differentiated type VIN is not associated with an HPV infection.

HPV infection alone is unlikely to cause VIN. Other factors that reduce the body's immune system may increase the risk of VIN. These factors include smoking, inherited immunity problems, certain medicines (for example those taken after transplant surgery), and some rare bone marrow and blood disorders.

Signs and symptoms of VIN

The signs and symptoms vary. They 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.

Some women have no symptoms and are diagnosed with VIN while having tests for other health problems. If you do have any of the symptoms mentioned here, let your doctor know. They 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).

How VIN is diagnosed

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 (a biopsy) to look at 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. A local anaesthetic is then injected into the area using a small needle. Very rarely a general anaesthetic may be needed.

The doctor will also examine your cervix and vaginal walls to look for any abnormalities in the cells.

Treatment for VIN

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.


Most women who need treatment will have the affected area removed with surgery called local surgical excision. Rarely, if the affected area is large or there are several areas, the whole vulva may be removed. This is called 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 treatment

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

The following treatments are newer treatment options. They are currently being investigated in research trials to see how useful they might be for VIN.


Imiquimod is a cream that you apply to the affected area. Your doctor will prescribe how often you should apply it and for how long. Imiquimod is a type of drug known as an antiviral drug. It stimulates the immune system to get rid of the HPV infection, which in turn allows 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. A trial is looking at using imiquimod and cidofovir to treat VIN. It is now closed to recruitment and awaiting results.

Photodynamic therapy (PDT)

PDT uses laser light to activate a light-sensitive drug. The drug is either given as a cream that’s 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 area(s). It reduces inflammation and can control symptoms, but it doesn't cure the condition.

Sometimes a local anaesthetic cream or gel can be used to ease any soreness or discomfort. Try to avoid using soap, as this can dry and irritate your skin. An emollient soap substitute is recommended to help moisturise and protect your skin instead.

Follow-up for VIN

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 you can be referred back to your hospital specialist.

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