This information is about a skin condition called vulval intra-epithelial neoplasia, or VIN, which can affect the vulva and, in some women, may develop into cancer after many years.

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 to 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 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 it is referred to as a pre-cancerous condition.

Although VIN used to be quite rare, it is now being recognised and diagnosed more frequently. It can affect women of any age from the 20s onwards, but is more common in women over 50.

VIN is often divided into three stages VIN 1, 2, and 3. These stages refer to how deeply the abnormal cells have gone into the surface layer of the vulva. Most women are diagnosed with VIN 3.

• VIN 1 – Only one third of the thickness of the surface layer of the vulva is affected.
• VIN 2 – Two thirds of the thickness of the surface layer of the vulva is affected.
• VIN 3 – The full thickness of the surface layer of the vulva is affected.

There are different types of VIN. The most common type is associated with an infection in the skin of the vulva by a type of virus known as human papilloma virus (HPV). HPV is a very common infection. There are over 100 types of the virus, and 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.

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.

Infection with HPV on its own may not cause VIN. Other factors that depress the body's immune system may also need to be present for VIN to occur. These include: smoking, particular medicines (such as those taken after transplant surgery) inherited immunity problems and some rare bone marrow and blood disorders.

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

• itching and soreness in the vulval area
• 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 vulval area
• raised areas of skin that can vary in size
• the skin having a warty appearance.

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 above symptoms, let your doctor know. Your doctor can then examine you and refer you to a doctor who specialises in women's health (a gynaecologist). However, the above symptoms can be caused by conditions other than VIN.

Your doctor will examine the vulval area and may use a special microscope (a colposcope), which magnifies the area so that any changes can be clearly seen. A small sample of cells from the affected area will be taken for examination under a microscope (biopsy). A local anaesthetic cream is usually used before the biopsy is taken. Once it has been applied, it usually takes around 20 minutes to numb the vulval area before the biopsy is taken. 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, using a biopsy tool.

The doctor may also examine the 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 you will need to have the area checked regularly by your doctor. Treatment may be needed for VIN 2 or 3. The type of treatment that is most appropriate for you will depend on:

• how abnormal the cells are
• the size of the affected area
• the estimated risk of the area developing into cancer.

If you smoke, giving up can help your immunity to become stronger, make the treatment more effective, and reduce the chance of the VIN coming back after treatment.

In certain situations, (for example, if you are pregnant), it may be possible to delay treatment for a time. In this situation the VIN would be closely monitored for any changes.

Surgery

In women who need treatment, most will have the affected area removed with surgery, known as local surgical excision. Rarely, if the affected areas are 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).

Laser ablation treatment may be used for areas where it is difficult to remove the VIN, such as around the clitoris. A high-energy laser beam is focused on the affected areas to destroy the abnormal cells.

Before any treatment, it is 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.

The following treatments may sometimes be used:

Diathermy

A tiny electrical current is passed through a probe, which is used to cut out the affected areas. A colposcope is used to identify these areas.

Medical treatments

Steroid cream The steroid cream is applied to the affected areas. It reduces inflammation and can control symptoms, but does not cure the condition.

Other possible treatments for VIN are being investigated. They are experimental at the moment, and include:

• imiquimod ointment, which is applied to the areas of VIN

• photodynamic therapy (PDT), PDT involves shining a laser onto the area of VIN which has been sensitised with a light-sensitive drug.

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 is 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 that they have VIN, and worry that they may develop cancer. You may find the treatments embarrassing and intimidating, and may feel tense, tearful, or withdrawn. At times, these feelings can be overwhelming and hard to deal with.

Everyone has their own way of coping with difficult situations. Some people find it helpful to talk to friends or family, while others prefer to seek help from people outside their situation. Others may prefer to keep their feelings to themselves. There is no right or wrong way to cope, but help is available if you need it.

This information has been compiled using information from a number of reliable sources including:

• Oxford Textbook of Oncology (3rd edition). Eds Souhami et al. Oxford University Press, 2005.
• Cancer and its Management (4th edition). Eds Souhami and Tobias. Oxford Blackwell Scientific Publications, 2003.
• Principles & Practice of Gynaecologic Oncology (3rd edition). Eds Hoskins et al. Lippincott, Williams and Wilkins, 2000.
• Liquid-based cytology for cervical screening (review). Technology Appraisal No. 69. National Institute for Clinical Excellence. October 2003.

For further references, please see the general bibliography.