Vulvar intraepithelial neoplasia (VIN)

This page was reviewed under our medical and editorial policy by

Ruchi Garg, MD, Chair, Gynecologic Oncology, City of Hope Atlanta, Chicago and Phoenix.

This page was reviewed on January 21, 2022.

Precancerous changes that occur in the surface layer of cells of the vulva are referred to as vulvar intraepithelial neoplasia (VIN). These abnormal cells develop slowly, and grow over the course of several years. In some cases, they may become cancerous (squamous cell carcinoma of the vulva). However, most cases of VIN don’t turn into cancer.

Based on the appearance of the cells and lesions present, vulvar intraepithelial neoplasia is classified as either usual-type VIN or differentiated-type VIN.

Usual-type VIN is caused by a human papillomavirus (HPV) infection and is more commonly found in women younger than age 50. It may develop into invasive vulvar squamous cell carcinoma. Some doctors grade usual-type VIN as VIN1, 2 or VIN3, with ascending numbers signifying increased severity.

Differentiated-type VIN isn’t caused by HPV infection; rather, it’s linked to conditions of the skin that affect the vulva called lichen sclerosus. This type of VIN is more commonly found in women older than age 60. As with usual-type VIN, it may develop into invasive vulvar squamous cell carcinoma.

While having vulvar intraepithelial neoplasia does increase your risk of developing vulvar cancer, it doesn’t guarantee that you will develop it. Your risk of cancer is higher with VIN3 than it’s with VIN1 or 2, but monitoring and treatment can greatly decrease the risk.

Expert cancer care

is one call away.
appointments in as little as 24 hrs.