Malignant Melanoma

What is Malignant Melanoma ?

Melanoma is a malignancy of pigment-producing cells (melanocytes) located predominantly in the skin, but also found in the eyes, ears, GI tract, leptomeninges, and oral and genital mucous membranes. Melanoma accounts for only 4% of all skin cancers; however, it causes the greatest number of skin cancer–related deaths worldwide. Early detection of thin cutaneous melanoma is the best means of reducing mortality.

Malignant melanoma currently accounts for approximately 1% of all cancer deaths. However, the worldwide incidence of melanoma is increasing at a faster rate than any other neoplasm, with the exception of lung cancer in women.

Causes of Malignant Melanoma

We are not certain how all cases of melanoma develop; however it is clear that excessive sun exposure, especially severe blistering sunburns during childhood, can promote melanoma development. There is also evidence that ultraviolet radiation used in indoor tanning equipment may also cause melanoma.

Signs & Symptoms of Malignant Melanoma

The first sign of melanoma is often a change in the size, shape, color, or feel of a mole on the skin. These changes can be remembered as "ABCD":

• Asymmetry - an odd shape, or one half is shaped differently from the other
• Border - ragged, notched, blurred, or irregular outline
• Color - different shades of black, brown, and tan in the same mole; there may also be patches of white, gray, red, pink, or blue in it
• Diameter - the mole grows larger; melanomas are usually larger than ¼ inch across

Diagnostic Tests

Excisional biopsy and full-depth punch biopsy with histologic examination can distinguish malignant melanoma from a benign nevus, seborrheic keratosis, or pigmented basal cell epithelioma and can also determine tumor thickness and disease stage.

Baseline laboratory studies may include complete blood count with differential, erythrocyte sedimentation rate, platelet count, and liver function studies, in addition to urinalysis.

Treatment

Treatment for melanoma begins with the dermatologic surgical removal of the melanoma and some normal appearing skin around the growth. Removal of the normal appearing skin is known as taking margins, and is done to be sure no melanoma is left behind. A person's outcome depends on how deep the melanoma is in the skin.

Numerous adjuvant therapies have been investigated for the treatment of localized cutaneous melanoma following complete surgical removal. No survival benefit has been demonstrated for adjuvant chemotherapy, nonspecific (passive) immunotherapy, radiation therapy, retinoid therapy, vitamin therapy, or biologic therapy.

In research setting other therapies, such as gene therapy, may be tested. Radioimmunotherapy of metastatic melanoma is currently under investigation.

Prevention Tips

Minimizing exposure to sources of ultraviolet radiation (the sun and sunbeds), sun protection measures and wearing protective clothing (long-sleeved shirts, long trousers, and broad-brimmed hats.) can offer protection. Using a sunscreen with an SPF rating of 30 or better on exposed areas has preventive effect