Vulval Intra-epithelial Neoplasia

What is the vulva?

The vulva is the external genital area of the female. It includes:

  • The labia majora. These are, in effect, large folds of skin.
  • The labia minora. These are more delicate folds of skin just inside the labia majora.
  • The clitoris – a small organ involved with sexual arousal.
  • Tiny glands, the most prominent being the Bartholin’s glands.
  • The entrance to the urethra – the tube through which urine is passed from the bladder.
  • The entrance to the vagina.

What is vulval intra-epithelial neoplasia?

Vulval intra-epithelial neoplasia (VIN) is a skin disorder that affects the vulva. What happens is that the cells of the skin of part, or several parts, of the vulva become abnormal and change in their appearance. It is called VIN as:

  • Vulval means affecting the vulva.
  • Intra-epithelial means that the condition is limited to within the skin cells (epithelium is a medical word for the top layer of skin).
  • Neoplasia means abnormal growth or proliferation of cells.

Note: VIN is not a cancer. The word neoplasia is sometimes used when talking of various cancers but its strict definition is an abnormal proliferation of cells. With VIN the cells are not cancerous.

However, in time, the cells of VIN in some affected women become cancerous. So, VIN is classed as a precancerous condition. (This is similar to the abnormal cells that are found in some women following cervical screening – previously called the cervical smear test. The abnormal cells that may be found in this situation are also usually precancerous and not actually cancer.)

VIN can develop anywhere on the vulva. One patch, or more than one patch of VIN may develop in different parts of the vulva.

VIN is subdivided (classified) into three groups:

  • VIN, usual type. There are various subtypes of this but, basically, the cause of all these subtypes is associated with the human papillomavirus (HPV).
  • VIN, differentiated type. This is much less common than VIN, usual type. This type is not usually associated with HPV.
  • VIN, unclassified type. This is rare.

Note: before 2004, VIN was classified into VIN 1, 2 and 3 which roughly meant mild, moderate and severe. The new classification came about in 2004 as agreed by the International Society for the Study of Vulvovaginal Diseases (ISSVD). However, there is some dispute among specialists as to whether to go along with the new classification. Some specialists retain the VIN 1, 2, 3 classification. This can be confusing! But, for the sake of simplicity, the rest of this leaflet will go along with the ISSVD classification.

What causes vulval intra-epithelial neoplasia?

The exact cause of VIN is not known. However, many cases are strongly linked to the human papillomavirus (HPV). There are over 100 different types (strains) of HPV. Two types, types 16 and 18, are particularly associated with the development of most cases of VIN. Type 31, and possibly some other types, may also be associated with VIN. Some other types of HPV cause common warts and verrucas. These types of HPV are not associated with VIN.

The types of HPV associated with VIN are nearly always passed on by having sex with an infected person. An infection with one of these types of HPV does not usually cause symptoms. So, you cannot tell if you are infected, or the person you have sex with is infected, with one of these types of HPV. In some women, the types of HPV that are associated with VIN affect the cells of the vulva. This makes them more likely to become abnormal, which may later (usually years later) turn into VIN.

Note: HPV infection is very common. But, within two years, 9 out of 10 infections with HPV will clear completely from the body. And, even if it remains in the body, most people infected with HPV do not go on to develop VIN. So, although most cases of VIN are associated with HPV, most women who are infected with HPV do not develop VIN.

HPV infection by itself may not directly cause VIN. It may be that other factors are needed in addition to HPV to cause VIN. Other factors that may possibly play a role in causing VIN include smoking and anything that depresses the immune system.

VIN, differentiated type, develops more commonly in women who have another vulval condition called vulval lichen sclerosus. It is also sometimes associated with a skin condition called lichen planus. See separate leaflets called ‘Lichen Sclerosus’ and ‘Lichen Planus’.

A similar condition to VIN can occur on other nearby parts of the body. When it affects the cervix it is called cervical intra-epithelial neoplasia (CIN). This is much more common than VIN, as it is what is looked for during the cervical screening test (previously called cervical smear test). Vaginal intra-epithelial neoplasia (VAIN) and anal intra-epithelial neoplasia (AIN) are uncommon. The cause of most cases of CIN, VAIN and AIN are also thought to be associated with infection by the HPV. If you have VIN, you have a higher than average risk of also developing one of these other related conditions.

How common is vulval intra-epithelial neoplasia?

VIN is uncommon (it is difficult to give exact figures). However, in recent years the number of cases seems to be rising gradually. Most women affected are over the age of 40. The average age of diagnosis is about 45-50 years. But, it can sometimes affect younger women and, rarely, can even affect teenagers.

What are the symptoms of vulval intra-epithelial neoplasia?

Sometimes there are no obvious symptoms, particularly when it first develops. So, unless you actually look at your vulva, you may not know VIN has developed. However, symptoms eventually usually do develop. A persistent itch in the vulva is the most common symptom. The itch may become severe. Other symptoms that may develop include soreness, burning or tingling in the vulva. Having sex may be painful.

VIN also usually causes a change in the appearance to the affected part or parts of the vulva. These include areas of redness, or white areas of skin. Sometimes affected areas of the vulva develop raised areas of skin.

So, in short, see a doctor if you have any persistent vulval symptoms or notice any changes to the skin or structures of the vulva. Some of the above symptoms and signs can be caused by various other conditions. But, a doctor will be able to examine you and assess you. If your doctor suspects VIN then he or she will refer you to a specialist.

How is vulval intra-epithelial neoplasia diagnosed?

The diagnosis can be confirmed by a biopsy of the affected area. A biopsy means a small sample of vulval skin is taken to be examined in the laboratory. The biopsy is usually done after using local anaesthetic to numb the area being sampled. The cells in the biopsy are examined under a microscope to look for the typical cells of VIN.

Do I need treatment?

If left untreated, VIN may go away by itself. However, most cases of VIN do not go away. Also, there is a risk that VIN may turn into cancer of the vulva at some point. Most cases of VIN do not develop into cancer. However, it is not possible to predict which cases will turn into cancer, and which ones won’t. If it does develop into cancer, on average, it takes over 10 years for VIN to develop into cancer.

So, due to the risk of cancer developing, treatment is usually recommended. However, an option sometimes considered is to keep the VIN under close regular observation by a specialist and to treat only if any changes into cancer develop.

What are the treatment options?

The aim of treatment is to remove or destroy all affected tissue. There are various treatment options. Your specialist will advise on the pros and cons of the different options. For example, the treatment advised may depend on factors such as the extent of the VIN – whether it is just in one small area or in two or more places in the vulva, and the exact subtype of VIN that you have. Treatments that may be options include the following:


A common treatment is to have the affected area or areas removed by an operation. Sometimes, if the VIN is extensive, the entire vulva is removed (vulvectomy). A skin graft (skin taken from another site in the body) may be needed if this is done.

Laser ablation

A laser can destroy the affected areas of the vulva. This is not commonly done these days as it can be painful, and there is a high rate of recurrence following this treatment.

Photodynamic therapy (PDT)

For this treatment, a drug is either applied topically (rubbed on to the vulva) or given as an injection into the bloodstream. The drug is taken up by the abnormal cells and is light-sensitive. A few hours later, a cold laser light is shone at the abnormal cells. This activates the light-sensitive drug, which has an effect of destroying the abnormal cells.

Imiquimod and similar drugs

Imiquimod is a drug that comes as a cream. You apply it topically (you rub it on to affected areas) each day for several weeks. Imiquimod is classed as an immune response modifier. This means that it boosts certain parts of the immune system. How it is thought to work for VIN is that it may boost the immune system to rid the affected cells of HPV (discussed earlier). This then allows the cells in the affected areas of vulva to return to normal. One side-effect is that imiquimod can cause inflammation and some women stop the treatment as a result of discomfort due to the inflammation.

Other similar drugs are being studied. For example, there is currently a research trial looking at the effects of imiquimod and another drug called cidofovir to assess their effects and side-effects when treating VIN. See here for details: http://cancerhelp.cancerresearchuk.org/trials/a-trial-of-two-new-treatments-for-vulval-intraepithelial-neoplasia

The advantages of PDT and imiquimod (and similar drugs) is that, if they work, there is no alteration in the appearance of the vulva as you would get with surgery.

Soothing treatments

The above treatments aim to cure the condition. However, in the meantime, you may benefit from soothing treatments. For example, whilst awaiting results of biopsies or awaiting treatment. These may help to ease any itch or discomfort but do not cure the condition. Your doctor may advise you to use a soothing bland cream on your vulva. Sometimes a steroid cream is used which aims to ease any inflammation or itch. Sometimes a local anaesthetic ointment may be advised to ease soreness.

It is also best to avoid using soaps, deodorants, etc, on the vulval skin as these can be irritating. To wash your vulva you can use a bland moisturiser such as emulsifying ointment instead of soap. You can also use the moisturiser to soothe the area as often as necessary.

What is the prognosis (outlook)?

All of the above treatments have a good chance of clearing VIN.

However, with any treatment, even when successful, there is a fair chance that the VIN will return at some point in the future. This is why, if you have VIN, you should have regular follow-up assessments with a doctor, even when treatment has been successful. This is typically a review appointment every 6-12 months. But, if you notice any symptoms or changes in your vulva between follow-up appointments, see your doctor promptly. Don’t wait for the next routine appointment.

Research continues to determine which treatment is likely to give the best chance of cure and least chance of a recurrence. Also, to look for newer, better treatments. For example, small research trials that looked at combining treatments (imiquimod followed by three doses of HPV vaccine, and imiquimod combined with PDT) showed promising results.

Can vulval intra-epithelial neoplasia be prevented?

The HPV vaccine has recently been introduced for girls from the age of 12 in the UK. Studies have shown that the HPV vaccine usually works very well to prevent HPV infection. As discussed earlier, HPV infection is a major factor in the development of VIN. The vaccine has been shown to work better for people who are given the vaccine when they are younger, before they are sexually active, compared with when it is given to adults.

It is likely that the number of cases of VIN will greatly reduce by the time the girls being vaccinated today reach adulthood – the age when VIN usually develops.

Smoking and VIN

It is thought that damaging chemicals from cigarette smoking may concentrate in the skin of the vulva and cervix, which can increase the risk of developing VIN and related disorders. If you smoke, giving up reduces your chance of developing VIN. If you have been treated for VIN and you smoke, giving up smoking can reduce your risk of VIN recurring in the future. For example, one research study concluded that women who continued to smoke after treatment for VIN were much more likely to have persistent or recurrent vulval disease compared with nonsmokers.

Further help and information

Vulval Awareness Campaign Organisation

Web: www.vaco.co.uk
Set up out of respect for women who have struggled with vulval diseases and disorders.

References and Disclaimer | Provide feedback


  • The Management of Vulval Skin Disorders, Royal College of Obstetricians and Gynaecologists (February 2011)
  • Terlou A, Blok LJ, Helmerhorst TJ, et al; Premalignant epithelial disorders of the vulva: squamous vulvar intraepithelial Acta Obstet Gynecol Scand. 2010 Jun;89(6):741-8. [abstract]
  • Fehr MK, Hornung R, Schwarz VA, et al; Photodynamic therapy of vulvar intraepithelial neoplasia III using topically Gynecol Oncol. 2001 Jan;80(1):62-6. [abstract]
  • Campbell SM, Gould DJ, Salter L, et al; Photodynamic therapy using meta-tetrahydroxyphenylchlorin (Foscan) for the Br J Dermatol. 2004 Nov;151(5):1076-80. [abstract]
  • Le T, Menard C, Hicks-Boucher W, et al; Final results of a phase 2 study using continuous 5% Imiquimod cream application Gynecol Oncol. 2007 Sep;106(3):579-84. Epub 2007 Jun 19. [abstract]
  • Winters U, Daayana S, Lear JT, et al; Clinical and immunologic results of a phase II trial of sequential imiquimod and Clin Cancer Res. 2008 Aug 15;14(16):5292-9. [abstract]
  • Daayana S, Elkord E, Winters U, et al; Phase II trial of imiquimod and HPV therapeutic vaccination in patients with Br J Cancer. 2010 Mar 30;102(7):1129-36. Epub 2010 Mar 16. [abstract]
  • Khan AM, Freeman-Wang T, Pisal N, et al; Smoking and multicentric vulval intraepithelial neoplasia. J Obstet Gynaecol. 2009 Feb;29(2):123-5. [abstract]
  • Sideri M, Jones RW, Wilkinson EJ, et al; Squamous vulvar intraepithelial neoplasia: 2004 modified terminology, ISSVD J Reprod Med. 2005 Nov;50(11):807-10. [abstract]


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