Vulvar intraepithelial neoplasia, or VIN, is a precancerous skin condition on the vulva, according to Baylor Clinic. It occurs when there are changes in the cells of the skin covering the vulva. VIN can develop anywhere on the vulva, said Patient.co.uk.
American Congress of Obstetricians and Gynecologists (ACOG) stated that VIN is an increasingly common problem, particularly among women in their 40s. Macmillan Cancer Support said that although VIN used to be quite rare, it's now being diagnosed more frequently. It can affect women from their 20s onwards.
Vulvar intraepithelial neoplasia is not cancer. Baylor Clinic said, however, if the changes become more severe, vulvar cancer may develop after many years.
The exact cause of VIN is unknown. It has been linked to human papillomavirus (HPV) which is a common infection, herpes simplex virus, granuloma inguinale (a sexually transmitted disease), smoking, immunosuppression, and chronic vulvar irritation, wrote Baylor Clinic.
VIN is classified into three groups.
The first is usual type VIN. Macmillan Cancer Support wrote usual type VIN can be further divided into warty, basaloid and mixed (warty, basaloid) types. ACOG said usual type VIN is commonly associated with human papillomavirus and other HPV persistence risk factors, such as cigarette smoking and immunocompromised status.
The second type is differentiated type VIN. Patient.co.uk said this is much less common than usual type VIN. ACOG continued saying differentiated type VIN usually is not associated with HPV and is more often associated with vulvar dermatologic conditions, such as lichen sclerosus.
Patient.co.uk said the third type, VIN-unclassified type, is rare.
Symptoms vary but may include chronic vulvar itching; burning, tingling or soreness in the vulva area; change in appearance of the affected area, including areas of redness or white, discolored skin; slightly raised skin lesions; some may appear darkened like a mole or freckle; and pain during sex, wrote Baylor Clinic.
In rare cases, there may be no symptoms initially.
If left untreated, VIN may go away by itself.