Vulval intra-epithelial neoplasia (VIN) describes changes that can happen in the skin that covers the vulva. VIN is not cancer. In some women, it can disappear without treatment.
If the changes become more severe, there is a chance that cancer might develop. So VIN is called a pre-cancerous condition.
VIN can affect women of any age from their 20s onwards. It is divided into two main types.
Vulval intra-epithelial neoplasia usual type (uVIN)
Nearly all VIN is usual type VIN (uVIN). This type is more common in younger women aged 35 to 55. It is associated with the human papilloma virus (HPV) – see below.
Vulval intra-epithelial neoplasia differentiated type (dVIN)
This type is rarer. It is more common in older women aged 55 to 85. It can often occur together with other skin conditions that can affect the vulva, such as lichen sclerosus or lichen planus. It is not usually associated with HPV.