Melanoma is tumor of the skin that is cancerous (malignant). It grows from the melanocytes, the cells that color and tan the skin. Melanoma is also called cutaneous melanoma or malignant melanoma. The incidence of melanoma is increasing worldwide at a rate of about 5% per year.
It is a more serious problem than the more common skin cancers, basal cell cancer or squamous cell cancer. Unlike these cancers, melanoma often will spread (metastasize) to other parts of the body. 96,480 new cases of melanoma are expected to be diagnosed in the US in 2019, with 7000 resulting in death.
It is the 5th most common cancer in men and 6th most common in women. For people 25 to 29, it the #1 most diagnosed cancer in the United States.
Melanoma can spread by local extension (through lymphatics) and/or by hematogenous routes (through the bloodstream) to distant sites. The risk of relapse may decrease over time, but late relapses are not uncommon.
Melanoma can appear on the body as a new mole, or one that has changed in size, shape, feeling or color, or developed oozing or bleeding. Adult men most often get melanoma on the trunk, especially between the shoulder blades, or on the head or neck. Women most often get melanoma on the arms and legs. It can rarely form in children.
Most melanomas are dark, but some are not, and may be flesh colored or pink to red. If there is a serious question of skin cancer, the mole or pigmented area will be cut out (local excision). This is usually done in a doctor's office. It is important that this remove the entire mole if possible.
The lab will analyze the removed skin. If melanoma is found they will report how deep and aggressive it appears. Then a physical exam and lab tests will be done to look for signs that cancer cells have spread to other parts of the body. This is called staging. A doctor needs to know the stage of the disease to plan treatment.
In the earliest melanomas, the abnormal cells are found only in the outer layer of skin cells and do not invade the body. It is more advanced if the growth goes deeper than 4 millimeters (less than 1/6 of an inch) into the skin. Most melanomas fall between these two extremes. More serious still are melanomas that have spread to the body tissue below the skin, show additional tumor around original tumor (satellite tumors), or have spread to lymph nodes or other organs.
Surgery is the primary treatment of all stages of melanoma. A second procedure is normally done to ensure complete removal of the melanoma. Complete removal of all the melanoma before it has spread is the only sure cure for melanoma. Usually, the biopsy site and a rim of apparently normal skin are removed. This is called a re-excision. The amount removed depends on how deep the melanoma has grown. Skin may have to be taken from another area of the body and put (or "grafted") where the cancer has been taken out.
Radiation therapy uses beams of energy to destroy cancer cells. It is usually done on the area where lymph nodes are removed in case any cancer cells remain.
Chemotherapy uses drugs to kill cancer cells. However, chemotherapy has not been shown to be very effective in treating melanoma. In the last 10 years, newer therapies have emerged which are finally decreasing the death rate of melanoma.
One of these therapies is immunotherapy which stimulates the body’s own immune system to fight cancer. Immunotherapy can be systemic or local. Systemic treatments travel through the bloodstream to reach all parts of the body, which is helpful if the melanoma has spread from its original location. Local treatments are injected directly into the melanoma lesions.
Another treatment is targeted therapy which is a medication that interferes directly with the function of abnormal molecules within tumor cells that regulate their growth. This slows down or stops the growth of melanoma cells without harming normal tissue.
The medical information provided in this site is for educational purposes only and is the property of the American Osteopathic College of Dermatology. It is not intended nor implied to be a substitute for professional medical advice and shall not create a physician - patient relationship. If you have a specific question or concern about a skin lesion or disease, please consult a dermatologist. Any use, re-creation, dissemination, forwarding or copying of this information is strictly prohibited unless expressed written permission is given by the American Osteopathic College of Dermatology.