Vulvovaginal Melanoma, from the CureRays guide library.

Vulvovaginal melanoma is a rare, aggressive melanoma that arises on the vulva or in the vagina rather than on sun-exposed skin; treatment combines surgery, radiation, and modern immunotherapy.

What it is.

Vulvovaginal melanoma is a melanoma — a cancer of the pigment-producing cells called melanocytes — that develops on the vulva or inside the vagina. Unlike the common skin melanomas linked to sun exposure, this is a 'mucosal' melanoma that arises on moist internal surfaces, so sunlight is not the cause and it often carries different gene changes (such as KIT or NRAS rather than the BRAF mutations typical of skin melanoma). It usually affects older women and may appear as a dark or sometimes colorless spot, a lump, bleeding, itching, or discharge — symptoms easily mistaken for something benign, which is one reason it is often found late. Because these tumors sit in a hidden area and tend to spread early, they are challenging to treat, but a combination of surgery, radiation, and immune-based therapy now offers better control than in the past.

How radiation treats it.

Radiation damages the DNA inside melanoma cells so they can no longer divide. Melanoma tends to respond best to large doses per session, so techniques like SBRT and brachytherapy — which concentrate a high dose precisely on the target — are particularly valuable here. After surgery, radiation to the tumor bed and nearby lymph nodes markedly lowers the chance the cancer returns in the pelvis. Radiation can also stimulate the immune system, which is why it is increasingly combined with immunotherapy. It is painless, delivered over a small number of sessions, and leaves no radioactivity behind.

The ways we can treat it.

Adjuvant external-beam radiation (IMRT/IGRT). Image-guided radiation to the tumor bed and at-risk nodes after surgery dramatically reduces local recurrence, shaping the dose around the bladder, rectum, and bowel.

Stereotactic body radiation (SBRT). Delivers a few high, focused doses; melanoma responds well to the large per-session doses SBRT provides, useful for the primary tumor or an isolated metastasis, and it pairs well with immunotherapy.

Brachytherapy. Radiation placed directly at the vaginal surface delivers a concentrated dose to the tumor or surgical bed while sparing surrounding organs.

Questions we hear often.

I avoided the sun — how did I get melanoma? Vulvovaginal melanoma is a mucosal melanoma that arises on internal surfaces, not sun-exposed skin, so sunlight is not the cause. It develops from pigment cells in the vulva or vagina and tends to carry different gene changes than ordinary skin melanoma — which also affects which drugs work best.

Will surgery be very extensive? Not necessarily. Surgeons now often favor removing the tumor with a clear margin while preserving as much function as possible, because very radical surgery has not been shown to improve survival. Radiation after surgery is frequently added to control the area, and immunotherapy treats the body as a whole.

How does immunotherapy help? Immune checkpoint inhibitors release the brakes on your immune system so it can attack melanoma cells, and they are central to treating advanced disease. They are increasingly combined with radiation, which can both control the tumor locally and help stimulate the immune response.

This guide is informational only. It is not medical advice — please confirm anything here with your care team.