Vulval intraepithelial neoplasia (VIN)

Vulval intra-epithelial neoplasia (VIN) describes abnormal changes of the cells that cover the vulva. VIN is not cancer, but it may develop into cancer after many years.

What is vulval intraepithelial neoplasia?

Vulval intra-epithelial neoplasia (VIN) describes abnormal changes of the cells that cover the vulva.

The vulva is the name given to all the visible sex organs that surround the opening of the vagina outside the body. People who have a vulva can include women, trans men and people assigned female at birth.

The vulva is made up of:

  • two thin, delicate folds of skin called the labia minora
  • two large, hair-covered folds called the labia majora – these surround the labia minora.

Between the labia are two openings:

  • the entrance of the vagina (birth canal)
  • the opening of the tube that drains urine from the bladder (the urethra).

Further back, under the legs, is the opening to the back passage (anus). The area of skin between the anus and vulva is called the perineum.

Is VIN cancer?

VIN is not cancer. The abnormal changes of the cells that cover the vulva may go back to normal naturally. But sometimes over time they develop into vulval cancer.

Other vulval skin conditions

There are other conditions that can affect the skin of the vulva. We have more information about:

Types of VIN

VIN is divided into two main types.

  • HSIL – High-grade squamous intraepithelial lesion of the vulva

    HSIL is more common. It is usually linked to a virus called HPV. This type was previously called VIN usual type (uVIN).

  • dVIN – VIN differentiated type

    dVIN is rarer. It often occurs together with other skin conditions that can affect the vulva, such as vulval lichen sclerosus (LS) or vulval lichen planus (LP). It is not usually linked to the HPV virus.

Symptoms of VIN

Sometimes VIN does not cause any symptoms. It may be found during tests for other health problems.

Symptoms may include:

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

Many people find it embarrassing talking about symptoms like these. But it is always important to get them checked by your GP. 

Causes and risk factors for VIN

Certain factors can increase your chance of developing VIN. Having one or more risk factor below does not mean you will get VIN. But not having any risk factors does not mean you will not get VIN.

HPV

The main cause of HSIL is an infection called the human papilloma virus (HPV). There are different types of HPV. The types that cause abnormal cell changes in the vulva are called high-risk HPV.

Usually the body’s immune system gets rid of the virus naturally. There are no symptoms and often the virus does not cause damage. Most people will never know they had it.

In some people, the immune system does not clear the infection and the virus stays in the body for longer. If the vulva is affected by HPV, it means the virus may cause damage that over a long time can develop into HSIL.

HPV is very common and most people have it at some point. The virus can live on the skin around the whole genital area. It passes easily from person to person during any type of sexual contact. This includes skin-to-skin genital contact or using sex toys.

This means that using a condom or other barrier contraception may reduce your risk of HPV infection, but it does not offer complete protection.

Smoking

Your risk of developing HSIL is much higher if you smoke. This may be because:

  • smoking makes your immune system less effective at clearing HPV
  • the chemicals in tobacco can damage your cells.

A weak immune system

Your immune system helps protect your body from infection and illness. A weak immune system is less likely to get rid of infections like HPV. You may have a higher risk of HSIL if your immune system is weakened over the long term, for example by:

  • smoking
  • some conditions, such as HIV
  • medicines used to suppress your immune system after an organ transplant.

If you are worried that you have a weakened immune system, talk to your GP or specialist nurse. They will be able to give you further advice.

Other vulval conditions

The main risk factor for dVIN is having another vulval condition such as vulval lichen sclerosus (VLS) or lichen planus (VLP).

Diagnosing VIN

If you have symptoms, you usually start by seeing your GP. If needed, they will refer you to doctor who specialises in vulval skin conditions (dermatologist or gynaecologist).

The main tests for VIN are an examination of the vulva and a simple procedure to collect a skin sample (biopsy) of any abnormal looking areas. Your doctor uses a local anaesthetic to numb the area before taking a sample. You can usually have this as an outpatient. It takes about 15 minutes.

The tests will show if you have VIN and the type of VIN. It will take about 7 to 10 days for the results of your biopsy to be ready. Waiting for your results can be difficult. It may help to talk to a relative or close friend.

Treating VIN

There are different types of treatment that can be used for VIN. The best treatment for you may depend on:

  • the part of the vulva affected by VIN
  • how many areas of VIN there are
  • if you have any symptoms
  • how likely it is that the VIN will develop into cancer (for example, the risk is higher if you have dVIN and vulval lichen sclerosus, or if you have a condition that weakens your immune system)
  • your personal preferences.

If you have a small area of VIN or you have no symptoms, you may not need treatment. Your doctor may ask you to have regular check-ups to look for any changes.

Sometimes, it may be possible to delay treatment. For example, you may delay treatment if you are pregnant. Your doctor will give you more information about the risks and benefits of this.

If you do need treatment, your doctor will explain your options and you will decide together. The aim is to improve any symptoms you have and reduce your risk of vulval cancer.

Surgery

The main treatment for VIN is usually a small operation to remove the affected area from the vulva. This is called a wide local excision.

Rarely, if the area is large or there are several areas, the whole vulva may be removed. This is called a vulvectomy. It is usually only considered when other treatments have not been successful or symptoms are difficult to manage.

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

Ablation treatment

Ablation treatments destroy the area of VIN. This treatment may be used when it is difficult to remove the VIN with surgery. For example, if the VIN is 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 set on the affected areas to destroy the abnormal cells.

Your doctor will tell you about your treatment. They will explain how much skin is going to be removed or treated, and how this will affect you afterwards.

Imiquimod

Imiquimod is a cream that uses your body’s immune system to get rid of VIN. You spread the cream on the areas of VIN. The treatment is usually for several months. You may need regular check-ups during this time.

Imiquimod can cause vulval inflammation and discomfort. This treatment may not be effective if you have a condition that weakens your immune system.

This treatment is not usually suitable for VIN differentiated type (dVIN). dVIN is usually removed rather than treated with cream as there is a higher risk of developing into vulval cancer.

Other treatments

Other treatments are sometimes used to treat VIN. Your doctor will explain if they may be suitable for you. Some treatments may only be available as part of a clinical trial.

Cidofovir

Cidofovir is a gel that you apply to the areas of VIN. Side effects include:

  • vulval inflammation
  • vulval discomfort
  • tiredness.

Photodynamic therapy (PDT)

This treatment uses laser light to activate a light-sensitive drug. The drug can be a cream applied to the vulva, or an injection into a vein (intravenously). The doctor will shine a laser light onto the affected area. This activates the drug to destroy the abnormal cells.

Managing VIN symptoms

Your doctor may give you advice and treatments to help you manage symptoms if these are a problem. These treatments may make you more comfortable, but they will not cure the VIN. This may include the following advice and treatments:

  • Steroid cream to apply to the affected area. You can use this for set amounts of time. Your doctor or nurse will explain this to you. The creams are not recommended for long-term use.
  • Local anaesthetic cream or gel to ease any soreness or discomfort.
  • Advice about skin care. For example, your doctor may tell you to avoid using soap or taking hot baths as this can dry and irritate your skin. Instead, use an emollient soap substitute to help moisturise and protect your skin. A vaginal moisturiser may help with discomfort too.

After treatment for VIN

VIN can come back after treatment, so you will see your specialist regularly, often for many years. They will check for signs of any further changes that may need treated.

If your risk of VIN returning is low, 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. They can organise for you to see your hospital specialist

If you smoke, giving up reduces the chance of the VIN coming back again. The NHS has a lot of information and support to help you give up smoking. If you want to stop smoking:

Your feelings

It can be difficult to know who to talk to or how to start a conversation about living with a vulval condition. But for many people, talking about it is an important way of coping.

You may find it helpful to talk to family or friends. Or you may prefer help from someone you are not close to, such as a counsellor. There is no right or wrong way to cope, but help is available if you need it. You may find the following organisations helpful:

Macmillan is also here to support you. If you would like to talk, you can:

About our information

  • Reviewers

    This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert medical and health professionals and people living with cancer. It has been approved by Senior Medical Editor, Professor Nick Reed, Consultant Clinical Oncologist.

    Our cancer information has been awarded the PIF TICK. Created by the Patient Information Forum, this quality mark shows we meet PIF’s 10 criteria for trustworthy health information.

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