The vulva is the external part of the female genital tract. It forms the opening of the vagina and includes the mons pubis, labia majora, labia minora, and clitoris. The vulva is composed of skin. The surface of the skin is called the epidermis and is mostly made up of squamous cells. The tissue beneath the epidermis is called the dermis, it contains blood vessels and connective tissue.
The most common type of vulvar cancer is squamous cell carcinoma. Most of these tumours are caused by human papillomavirus (HPV) and arise from a precancerous condition called high grade squamous intraepithelial lesion (HSIL). Tumours not associated with HPV often arise from a precancerous condition called differentiated vulvar intraepithelial neoplasia (dVIN).