Vulval intraepithelial neoplasia (VIN)
What is vulval intraepithelial neoplasia?
Vulval intraepithelial neoplasia (VIN) describes abnormal changes of the cells that cover the vulva. It is also called high-grade squamous intraepithelial lesions (HSIL).
Vulvas are the visible sex organs that surround the opening of the vagina outside the body. People who have a vulva include women, transgender (trans) men and people assigned female at birth.
The vulva is made up of:
- 2 thin, delicate folds of skin called the labia minora
- 2 large, hair-covered folds called the labia majora – these surround the labia minora.
Between the labia are 2 openings:
- the entrance of the vagina – this is the birth canal
- the opening of the urethra – this is the tube that drains urine from the bladder.
Further back, in between the buttocks, 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 over a long time without treatment, sometimes VIN could 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 2 main types:
- VIN usual type (uVIN) is more common. It is usually linked to a virus called HPV. This type is also called high-grade squamous intraepithelial lesion of the vulva (HSIL).
- VIN differentiated type (dVIN) is rarer. It often occurs together with other skin conditions that can affect the vulva, such as LS or LP. It is not usually linked to HPV.
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, which can become worse when passing urine (peeing)
- 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 usual type
Certain factors can increase your chance of developing VIN. Having 1 or more risk factor 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 VIN 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 VIN.
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 VIN 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.
We have information to help you stop smoking.
A weak immune system
The immune system helps protect the 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 VIN if your immune system is weakened over a long time. For example, this may be because of:
- smoking
- some conditions, such as human immunodeficiency virus (HIV)
- medicines used to suppress the immune system – for example, 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 lichen sclerosus (LS) or lichen planus (LP).
Diagnosing VIN
If you have symptoms, you usually start by meeting with your GP. They may refer you to a doctor who specialises in vulval skin conditions – this is a dermatologist or gynaecologist.
The main tests for VIN are:
- an examination of the vulva
- a simple procedure to collect a skin sample of any areas that look abnormal – this is called a biopsy.
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 biopsy results will show whether 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.
Related pages
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
- whether 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 a condition that weakens your immune system
- your personal preferences.
Sometimes, it may be possible to delay treatment. For example, you may decide to delay treatment if you are pregnant. Your doctor will give you more information about the risks and benefits of this.
If you need treatment, your doctor will explain your options and you will decide together. The aim is to improve any symptoms you have and reduce the 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 very large or there are several areas, the surgeon may suggest removing the whole vulva. This is called a vulvectomy. It is usually only considered when other treatments have not been successful or if symptoms are difficult to manage.
We have more about both these types of surgery in our information on 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 such as a laser, which destroys 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 the 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. It may also cause headaches and tiredness (fatigue).
This treatment may not be effective if you have a condition that weakens your immune system.
Imiquimod is not suitable for VIN differentiated type (dVIN). dVIN is usually removed as there is a higher risk of it developing into vulval cancer.
Other treatments
Other treatments are sometimes used to treat VIN. Your doctor will explain whether they may be suitable for you. Some treatments may only be available as part of a clinical trial.
Managing VIN symptoms
Your specialist doctor or nurse 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 local anaesthetic cream or gel to ease any soreness or discomfort.
Your specialist doctor or nurse may also tell you to avoid using soap or taking hot baths, as this can dry and irritate your skin. Instead, use a moisturising non-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 meet with your specialist regularly, often for many years. They will check for signs of any further changes that may need treatment.
If the risk of VIN coming back 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, stopping reduces the chance of the VIN coming back. The NHS has a lot of information and support to help you stop smoking. If you want to stop smoking, contact:
- NHS Smokefree in England
- Stop Smoking in Scotland
- Help Me Quit in Wales
- Stop Smoking in Northern Ireland.
Your feelings
It can be difficult to know who to talk to, or how to start a conversation about living with this skin 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.
Further information and support
The British Society for the Study of Vulval Disease offers patient information and useful links to information about vulval conditions.
Macmillan Cancer Support is also here to support you. If you would like to talk, you can:
- call the Macmillan Support Line on 0808 808 00 00
- chat to our specialists online.
About our information
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.
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References
Below is a sample of the sources used in our vulval cancer information. If you would like more information about the sources we use, please contact us at informationproductionteam@macmillan.org.uk
Morrison J, Baldwin P, Hanna L, Andreou A, Buckley L, Durrant L, et al. British Gynaecological Cancer Society (BGCS) vulval cancer guidelines: An update on recommendations for practice 2023. European Journal of Obstetrics and Gynaecology and Reproductive Biology. 2024;292: 210–238. Available from: www.doi.org/10.1016/j.ejogrb.2023.11.013 [accessed July 2026].
The Royal College of Radiographers. The Royal College of Radiologists expert panel recommendations for radiotherapy treatment for vulval cancer. 2024. Available from: www.rcr.ac.uk/media/l1zjohkm/rcr-vulval-cancer-treatment-recommendations.pdf [accessed July 2026]
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