Differentiated vulvar intraepithelial neoplasia (dVIN) is a pre-cancerous disease that develops in the vulva. It is called a pre-cancerous disease because over time it can turn into a type of vulvar cancer called squamous cell carcinoma.
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 made 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.
Differentiated vulvar intraepithelial neoplasia (dVIN) is often associated with an inflammatory condition called lichen sclerosus. People who develop this dVIN have usually had lichen sclerosus for many years. Unlike other pre-cancerous diseases in the vulva, dVIN is not caused by a virus called human papillomavirus (HPV).
The first diagnosis of dVIN is usually made after a small sample of tissue is removed in a procedure called a biopsy. A larger surgical procedure, for example, an excision or vulvectomy, may be performed later to remove the disease and look for any evidence of squamous cell carcinoma.
When examined under the microscope the tumour cells in dVIN look abnormal compared to the surrounding healthy squamous cells. In particular, the tumour cells are larger and the nucleus in the centre of the cell is darker. Pathologists describe these cells are hyperchromatic.
A margin is any tissue that has to be cut by the surgeon in order to remove the tumour from your body. A negative margin means that no tumour cells were seen at the cut edge of the tissue. In contrast, a positive margin means that tumour cells were seen at the cut edge of the tissue. A positive margin increases the risk that the tumour will grow back in that location.