Types Squamous cell carcinomas account for about 86 percent of all vulvar malignancies. Melanoma accounts for another 6 percent, adenocarcinoma of the Bartholin's gland for 4 percent, sarcomas for 2 percent, basal cell carcinoma for 2 percent and Paget's disease for 0.5 percent of all vulvar cancers.
Some physicians believe that the grade of the tumor cells as seen under the microscope is also significant. Immature, or undifferentiated , cells are more virulent and aggressive. Grade 1 (mature, or well-differentiated) cancers have a better prognosis than Grade 3 (poorly differentiated) tumors.
How It Spreads Squamous cell carcinoma arises in the skin of the genitalia and stays confined to the skin for an estimated 1 to 10 years. (At this stage, it is referred to as a carcinoma in situ or vulvar intraepithelial neoplasia—VIN.) Eventually it becomes invasive. With time it becomes locally destructive, growing to involve the urethra, vagina and the anus. It can also spread through the lymphatic system to the lymph nodes in the groin, then to the lymph nodes in the pelvis. Distant metastases, most frequently to the lungs and liver, are relatively rare ( See "Cancers of Female Pelvic Organs" ).
What Causes It Like carcinoma of the cervix , the risk factors for the development of vulvar cancer are primarily related to the likelihood of exposure to the sexually transmitted human papilloma virus (HPV).
