Understanding Vulvar Intraepithelial Neoplasia (VIN)

Vulvar intraepithelial neoplasia (VIN) is a precancerous¹ area of the skin on the vulva. Having a VIN diagnosis does not mean cancer.

VIN can spontaneously disappear and is not invasive, however if it is left untreated around 15 per cent of those with VIN will develop cancer^2,3 (vulvar squamous cell cancer (SCC)). This type of skin cancer is not the same as extramammary Paget’s disease or a vulval in-situ melanoma.

VIN can also be called vulvar squamous intraepithelial lesion (SIL), and was formerly known as Bowen disease of the vulva^4,5. For the purposes of this article, we’ll call it VIN.

Symptoms of vulval intraepithelial neoplasia

Mild or severe vulval itch⁶
Burning vulva⁶
Slightly raised, defined skin lesions that could be pink, red, brown or white⁶

Who gets vulvar intraepithelial neoplasia?

VIN can occur at any age, though younger women – including teenagers – are now presenting with the disease. The average age of diagnosis is between 45 and 50.

Half of all cases of VIN are caused by HPV (types 16 and 18), however HPV also causes genital warts and other cancers (cervical, vaginal, anal). Around half of women with VIN have a history of abnormal cervical pap smears or cancers.

Smoking cigarettes is a risk factor for VIN and other cancers of the lower genital tract. Immunosuppression by medication or diseases can also contribute.

These symptoms can be linked with lichen sclerosus or erosive lichen planus.

Diagnosis of vulvar intraepithelial neoplasia

Diagnosis is made using the appearance – irregular red or white/pigmented plaques and lesions on the vulva can indicate VIN.

A colposcopy is used to look at the skin in greater depth, and a biopsy is necessary to confirm a diagnosis of VIN and to establish the type of cancer. Postmenopause, it is normal procedure for any wart-like growth to be biopsied.

Classifications of vulvar intraepithelial neoplasia

There used to be three classifications of VIN, with VIN 1 (below) being a self-limiting infection caused by HPV. ‘Self-limiting’ means it heals by itself, and then goes away.

The three-grade system was upgraded in 2004 with a single-grade system, whereby only high-grade VIN (see 2 and 3 below) were called VIN.

The three classifications of vulvar intraepithelial neoplasia

Low-grade squamous intraepithelial lesion (flat condyloma (wart) or HPV effect) (not considered abnormal growth (neoplastic))
High-grade squamous intraepithelial lesion (VIN usual type) (can progress to invasive squamous cell carcinoma, very heavily associated with HPV and HPV risk factors including smoking and immune deficiency)
Intraepithelial neoplasia, differentiated-type (can progress to invasive squamous cell carcinoma very quickly, not usually associated with HPV,but with lichen sclerosus and other dermatological conditions affecting the vulva)

Treatment for vulvar intraepithelial neoplasia

Low-grade versions of VIN don’t always need treatment, however observation is required until lesions resolve, or if they progress to high-grade VIN.

High-grade and differential VIN lesions are treated to prevent invasive cancer, with the goal to remove all tissues affected, with a small margin to be sure. This removal is almost always done surgically, however, a vulvectomy may be required (removal of all or part of the vulva) due to the spread of the lesions or advanced disease.

If there is no cancer present, lasers can be used to remove affected tissue.

Medicine can be used to treat some types of vulvar intraepithelial neoplasia

Imiquimod cream – 3 times daily for 12-20 weeks – can be very uncomfortable, since the skin becomes red, inflamed and eroded.
5-fluorouracil cream – 2 times daily for 2-3 weeks – causes severe inflammation for weeks, and is intolerable for many women. Less effective than imiquimod cream.
Photodynamic therapy (PDT) – specialised equipment, may be painful
Cidovir has proven useful for some women

There is no official treatment for VIN, and recurrence rates are high, sitting at about 30 or so per cent. Recurrence rates are increased in immunosuppression, incomplete removal or in combination with other diseases.

How to help yourself if you have been diagnosed with VIN

Stop smoking – it has a direct link with VIN
HPV vaccines have shown to decrease the risk of VIN, cervical cancer, and genital warts
Treat or manage underlying lichen sclerosus when present

The prognosis of a VIN diagnosis

Untreated low-grade VIN often resolves by itself (in particular the version previously known as Bowenoid papulosis). It usually takes a decade or so for HPV-linked VIN to turn into cancer, but it can quickly turn cancerous in differentiated VIN.

Follow-up treatment is essential over the long term, and is advised every 6-12 months up to five years after surgery.

Up to half of all those diagnosed with VIN also develop:

Precancerous cervical cells (intraepithelial neoplasia, CIN)
Anal cancer (anal intraepithelial neoplasia, AIN)
Vaginal cancer (vaginal intraepithelial neoplasia, VAIN),
Other invasive cancers of the genitals or anus

Regular smears are critical.

Can natural medicine be used when treating VIN?

Natural medicine can act in a supportive way when dealing with a diagnosis of vulvar intraepithelial neoplasia. Because the cells are not cancerous (and may never become cancerous), there is an opportunity to boost the immune system to protect cells before they can become cancerous.

Natural medicine can play an important role in VIN, with adjunctive therapies alongside any treatments recommended by your primary practitioner available.

Effective ways you can support your immune system include herbal medicine, acupuncture, diet, and prioritising important elements like sleep, exercise, and stress.

Seek out a qualified, experienced practitioner to support you. The goal is to be as healthy as possible, resolving any underlying issues that may be contributing to lowered immunity and these changes.

References

1.
de Jong E, Leeman A, Bouwes Bavinck JN. Precancerous Manifestations. Atlas of Dermatologic Diseases in Solid Organ Transplant Recipients. Published online 2022:253-302. doi:10.1007/978-3-031-13335-0_11
2.
Scurtu LG, Scurtu F, Dumitrescu SC, Simionescu O. Squamous Cell Carcinoma In Situ—The Importance of Early Diagnosis in Bowen Disease, Vulvar Intraepithelial Neoplasia, Penile Intraepithelial Neoplasia, and Erythroplasia of Queyrat. Diagnostics. Published online August 16, 2024:1799. doi:10.3390/diagnostics14161799
3.
Thuijs NB, van Beurden M, Bruggink AH, Steenbergen RDM, Berkhof J, Bleeker MCG. Vulvar intraepithelial neoplasia: Incidence and long‐term risk of vulvar squamous cell carcinoma. Intl Journal of Cancer. Published online July 22, 2020:90-98. doi:10.1002/ijc.33198
4.
Wilkinson EJ, Cox JT, Selim MA, O’Connor DM. Evolution of Terminology for Human-Papillomavirus-Infection-Related Vulvar Squamous Intraepithelial Lesions. Journal of Lower Genital Tract Disease. Published online January 2015:81-87. doi:10.1097/lgt.0000000000000049
5.
Bornstein J, Bogliatto F, Haefner HK, et al. The 2015 International Society for the Study of Vulvovaginal Disease (ISSVD) Terminology of Vulvar Squamous Intraepithelial Lesions. Journal of Lower Genital Tract Disease. Published online January 2016:11-14. doi:10.1097/lgt.0000000000000169
6.
Bogliatto F. Vulvar Intraepithelial Neoplasia. Vulvar Disease. Published online 2019:371-378. doi:10.1007/978-3-319-61621-6_55