What is vulvar cancer?
The vulva is the outer part of the female genitals. The vulva includes the opening of the vagina (sometimes called the vestibule), the labia majora (outer lips), the labia minora (inner lips), and the clitoris.
Around the opening of the vagina, there are 2 sets of skin folds. The inner set, called the labia minora, are small and hairless. The outer set, the labia majora, are larger, with hair on the outer surface. These inner and outer labia (Latin for lips) meet, protecting the vaginal opening and, just above it, the opening of the urethra (the short tube that carries urine from the bladder). The Bartholin glands are found just inside the opening of the vagina -- one on each side. These glands produce a mucus-like fluid that acts as a lubricant during sex.
At the front of the vagina, the labia minora meet to form a fold or small hood of skin called the prepuce. The clitoris is beneath the prepuce. The clitoris is an approximately ¾-inch structure of highly sensitive tissue that becomes swollen with blood during sexual stimulation. The labia minora also meet at a place just beneath the vaginal opening, at the fourchette. Beyond the fourchette is the anus, the opening to the rectum. The space between the vagina and the anus is called the perineum.
Cancer of the vulva (also known as vulvar cancer) most often affects the inner edges of the labia majora or the labia minora. Cancer occurs on the clitoris or in the Bartholin glands less often.
Types of vulvar cancer
Squamous cell carcinomas
Most cancers of the vulva are squamous cell carcinomas. This type of cancer begins in squamous cells, the main type of skin cells. There are several subtypes of squamous cell carcinoma. The keratinizing type is most common, and usually develops in older women, and is not linked to infection with human papilloma virus (HPV) (HPV is discussed in the section “What are the risk factors for vulvar cancer?”). Basaloid and warty types are less common, and are the kinds more often found in younger women with HPV infections. Verrucous carcinoma is an uncommon subtype that is important to recognize because it is slow-growing and tends to have a good prognosis (outlook). This cancer looks like a large wart and a biopsy is needed to determine it is not a benign (non-cancerous) growth.
Cancer that begins in gland cells is called adenocarcinoma. About 8 of every 100 vulvar cancers are adenocarcinomas. Vulvar adenocarcinomas most often start in cells of the Bartholin glands. These glands are found just inside the opening of the vagina. A Bartholin gland cancer is easily mistaken for a cyst (accumulation of fluid in the gland), so a delay in accurate diagnosis is common. Most Bartholin gland cancers are adenocarcinomas. Adenocarcinomas can also form in the sweat glands of the vulvar skin.
Paget disease of the vulva is a condition in which adenocarcinoma cells are found in the top layer of the vulvar skin. Up to 25% of patients with vulvar Paget disease also have an invasive vulvar adenocarcinoma (in a Bartholin gland or sweat gland). In the remaining patients, the cancer cells are found only in the skin's top layer and have not grown into the tissues below.
Melanomas develop from the pigment-producing cells that give skin color. They are much more common on sun-exposed areas of the skin, but can start in other areas, such as the vulva. Around 5 of every 100 melanomas in women occur on the vulva, usually on the labia minora and clitoris. They make up about 6 of every 100 vulvar cancers. More information about melanoma can be found in our document Melanoma Skin Cancer.
A sarcoma is a cancer that begins in the cells of bones, muscles, or connective tissue. Less than 2 of every 100 vulvar cancers are sarcomas. Unlike other cancers of the vulva, vulvar sarcomas can occur in females at any age, including in childhood.
Basal cell carcinoma
Basal cell carcinoma, the most common type of skin cancer, is more often found on sun-exposed areas of the skin. It occurs very rarely on the vulva. For more information on this type of cancer, see our document Skin Cancer: Basal and Squamous Cell.
Last Medical Review: 02/05/2013
Last Revised: 02/05/2013