The vulva is the external part of the female genitals, including the clitoris, the vaginal lips, the opening to the vagina, and the surrounding skin and tissue. Most vulvar cancers are squamous cell carcinoma.
This type of cancer begins in squamous cells (thin, flat skin cells) and is usually found on the vaginal lips. A small number of vulvar cancers are adenocarcinomas (cancers that begin in cells that make mucus and other fluids). This type of cancer is usually found on the sides of the vaginal opening.
Vulvar cancer usually forms slowly over a number of years. Abnormal cells can grow on the surface of the vulvar skin for a long time. This condition is called vulvar intraepithelial neoplasia (VIN).