Vaginal melanoma is a rare

malignancy Malignancy () is the tendency of a medical condition to become progressively worse. Malignancy is most familiar as a characterization of cancer. A ''malignant'' tumor contrasts with a non-cancerous ''benign'' tumor in that a malignancy is not s ...

that originates from

melanocytes Melanocytes are melanin-producing neural crest-derived cells located in the bottom layer (the stratum basale) of the skin's epidermis, the middle layer of the eye (the uvea), the inner ear, vaginal epithelium, meninges, bones, and heart. ...

in the

vaginal epithelium The vaginal epithelium is the inner lining of the vagina consisting of multiple layers of (squamous) cells. The basal membrane provides the support for the first layer of the epithelium-the basal layer. The intermediate layers lie upon the basal ...

. It is also known as a

melanocytic tumor Melanocytic tumors are neoplasm, tumors developed from melanocytes. Types

* Melanocytic nevus * Melanocytic tumors of uncertain malignant potential * Melanoma Tumor {{med-sign-stub ...

or as a malignant

melanoma Melanoma, also redundantly known as malignant melanoma, is a type of skin cancer that develops from the pigment-producing cells known as melanocytes. Melanomas typically occur in the skin, but may rarely occur in the mouth, intestines, or eye ( ...

. It is aggressive and infrequently cured. The median overall survival is 16 months. Vaginal melanoma accounts 5.5% of all vaginal cancers and only 1% of all melanomas diagnosed in women. Vaginal melanomas are frequently diagnosed in advanced stages of the disease. The prognosis is poor and the most important risk factor is the presence of lymph node metastases.

Presentation

This cancer most often develops on the lowest third of the vagina. It is darkly pigmented and of an irregular T-shape, but amelanotic melanomas have been described in 7% of cases. Melanoma of the vagina can be several centimeters in size.

Histology

When the tissue is assessed, the histological characteristics include: * the shape of the cells appear similar to epithelial and spindle-shaped * the growth occurs in the shapes of sheets and nests * the presence of

melanin Melanin (; from el, μέλας, melas, black, dark) is a broad term for a group of natural pigments found in most organisms. Eumelanin is produced through a multistage chemical process known as melanogenesis, where the oxidation of the amino ...

in the cells * the nucleus of the cells is large and abnormal

Other cancers

Other cancerous conditions arise from vaginal epithelium: *

Vaginal squamous-cell carcinoma Squamous-cell carcinoma of the vagina is a potentially invasive type of cancer that forms in the tissues of the vagina. Though uncommon, squamous-cell cancer of the vagina (SCCV) is the most common type of vaginal cancer. It is further subdivide ...

arises from the

squamous cell Epithelium or epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly packed cells with a little intercellula ...

s of the vaginal epithelium * Vaginal adenocarcinoma arises from secretory cells in the vaginal epithelium * Clear cell adenocarcinoma of the vagina this malignancy arises in some women prenatally exposed to

diethylstilbestrol Diethylstilbestrol (DES), also known as stilbestrol or stilboestrol, is a nonsteroidal estrogen medication, which is presently rarely used. In the past, it was widely used for a variety of indications, including pregnancy support for those with a ...

Diagnosis

A biopsy should be obtained from all suspicious lesions and

Immunocytochemistry Immunocytochemistry (ICC) is a common laboratory technique that is used to anatomically visualize the localization of a specific protein or antigen in cells by use of a specific primary antibody that binds to it. The primary antibody allows visual ...

can reveal positive results for S-110 protein, HMB 45 and melan A. Once the diagnosis of vaginal melanoma is established, additional examinations should be performed to exclude the spread to regional lymph nodes or distant organs, as the diagnosis of vaginal melanoma is often delayed. Lymph-node involvement is the most important prognostic factor.

Treatment

Surgery represents the primary treatment modality. Chemotherapy may be ineffective, but checkpoint inhibitors and BRAF and MEK inhibitors have been recently tested in vaginal melanomas. Less than 10% of vaginal melanomas have BRAF-mutations. Therefore BRAF-inhibitors play only a minor role in vaginal melanomas (unlike in skin

melanomas Melanoma, also redundantly known as malignant melanoma, is a type of skin cancer that develops from the pigment-producing cells known as melanocytes. Melanomas typically occur in the skin, but may rarely occur in the mouth, intestines, or eye (u ...

). However, a recent study has shown that checkpoint inhibitors (inkluding CTLA-4 inhibitors and PD-1 inhibitors) are effective in the treatment of advanced vulvovaginal melanomas.

References

External links

* Melanoma Vaginal diseases Disturbances of human pigmentation Epithelium {{Women's health stub