What is vulval intraepithelial neoplasia?

Vulval intraepithelial neoplasia (VIN) describes changes that can happen in the skin that covers the vulva. VIN is not cancer. In some women, it can disappear without treatment.

If the changes become more severe, there is a chance that vulval cancer might develop. So VIN is called a pre-cancerous condition.

VIN can affect women of any age from their 20s onwards.

Types of VIN

VIN is divided into two main types.

  • Vulval intraepithelial neoplasia usual type (uVIN)
    Nearly all VIN is usual type VIN (uVIN). This type is more common in younger women aged 35 to 55. It is associated with the human papilloma virus (HPV).
  • Vulval intraepithelial neoplasia differentiated type (dVIN)
    This type is rarer. It is more common in older women aged 55 to 85. It can often occur together with other skin conditions that can affect the vulva, such as lichen sclerosus or lichen planus. It is not usually associated with HPV.

Some very rare types of VIN do not fit into either of these categories. They are called unclassified type.

Symptoms of VIN

Some women have no symptoms. They may not know they have VIN unless it is diagnosed while having tests for other health problems.

The signs and symptoms of VIN may include some or all of the following:

  • itching and soreness of the vulva
  • pain in the area of the vulva
  • burning or tingling of the vulva, that can become worse when passing urine
  • thickened, raised, red, white or dark patches on the skin of the vulva
  • the skin of the vulva having a warty appearance
  • pain during sex.

All of these symptoms can happen with conditions other than VIN, but it is always important to get them checked by your GP.

Causes of VIN


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

HPV is a very common infection. It is usually passed between people during sex. There are more than 100 types of HPV, and each has a number. Some types (particularly 16, 18 and 33) are linked to VIN and vulval cancer.


If you smoke you are more likely to develop VIN, as smoking weakens the body’s immune system.

Help is available if you want to give up smoking. Ask your GP for advice.

Lowered immunity

The immune system is part of the body’s defence against infections. Having a lowered immunity because of illness or treatment can increase the risk of VIN. This could be if:

  • you have HIV
  • you are taking medicines to suppress your immune system after an organ transplant.

If you are worried that you are at risk of developing VIN because you have lowered immunity, talk to your GP or specialist nurse, if you have one. They will be able to give you further advice.

Diagnosing VIN

Your GP will examine you. If necessary, they will refer you to a doctor who specialises in women's health (a gynaecologist).

The gynaecologist will examine your vulva and may use a special microscope (a colposcope). This 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 they take a biopsy, they use a local anaesthetic cream or injection to numb the area. This will take a few minutes to work. Rarely, you may need a general anaesthetic.

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

Treating VIN

Not all women will need treatment. The treatment of VIN often depends on:

  • how large the affected area is
  • whether you have any symptoms
  • the estimated risk of the area developing into cancer.

If you have a small area of VIN or you have no symptoms, treatment may not be recommended. But your doctors may suggest that you have the area checked regularly for any changes.

The aim of treatment is to remove or destroy the affected area.

If you smoke, giving up can help to:

  • strengthen your immunity
  • make the treatment more effective
  • 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 are pregnant). In this case, the VIN would be closely monitored for any changes.


Most women who need treatment will have the affected area removed with surgery. The operation is called a 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). A vulvectomy is usually only considered when other treatments have not been successful or symptoms are difficult to manage.

We have more about these types of surgery in our information about surgery for vulval cancer.

Ablation treatment

Ablation means destroying the affected area. It may be used for areas where it is difficult to remove the VIN with surgery, for example around the clitoris. Ablation can be done using:

  • a high-energy beam (laser)
  • 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 treatment, it is important that you know exactly how much skin is going to be removed or treated, and how this will affect you afterwards. Your specialist can discuss this with you before you have the treatment.

Other treatments for VIN

The following treatments are newer treatment options that may sometimes be used.


Imiquimod is a cream that you apply to the affected area. Imiquimod is a type of drug known as an antiviral drug. It stimulates the immune system to get rid of the HPV infection. This allows the vulva cells to return to normal.

The main side effect of this treatment is inflammation and discomfort of the affected area.


Cidofovir is a gel that you apply to the affected area. It is another type of antiviral drug. Side effects include inflammation and discomfort of the affected area and tiredness.

Cidofovir may be helpful for some women with VIN, but more research is needed to find out how useful it is.

Photodynamic therapy PDT

PDT uses laser light to activate a light-sensitive drug. The drug is given either as a cream applied to the vulva, or as an injection into a vein (intravenously). The doctor then shines a laser light onto the affected area. This 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. It reduces inflammation and can control symptoms, but it does not cure the condition.

Steroid creams are used for set amounts of time. Your doctor, nurse or pharmacist will explain this to you. The creams are not recommended for long-term use.

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.

After treatment for VIN

There is a risk that VIN can come back after treatment, so you will see your specialist regularly, 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 is important to let your GP know so you can be referred back to your hospital specialist.

Your feelings

Everyone has their own way of coping with difficult situations. Some people find it helpful to talk to family or friends. Others prefer to seek help from people outside of their situation, such as a counsellor. Some people prefer to keep their feelings to themselves. There is no right or wrong way to cope, but help is available if you need it. Our cancer support specialists can give you support and information about counselling in your area.