Skin Cancer: 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.

Anyone can get melanoma, but fair skinned sun sensitive people are at greater risk. Ultraviolet radiation from the sun is a major culprit, and people who tan poorly or burn easily are at the greatest risk. While to much sun is a bad idea throughout life, sunburns in children and teenagers seem to be the most damaging.

In addition to sunburns early in life, people with many moles are at greater risk to develop melanoma. Everyone has moles, usually around 30, and most are without significance. However, people with more than 50 moles are at an increased risk. In addition to the number of moles, some moles are unusual and irregular looking. These moles are known as dysplastic or atypical moles. People with atypical (dysplastic) moles are at increased risk of developing melanoma. Melanoma does run in families. If a close relative, such as a parent, aunt or uncle, has had melanoma, then other blood relatives are at increased risk for melanoma.

All of these features, fair skinned, sun sensitive people, a history of sunburns, many moles, atypical moles, and close relatives who had melanoma, allow us to identify those at risk for developing melanoma. Anyone, even those with none of the risk factors, can develop melanoma, but people with one or more of the risk factors are more likely to do so. If you have some of these risk factors, periodic routine skin examinations by your dermatologists can truly be life saving.

Almost always, melanoma begins on the surface of the skin where it is easily treated. However, if given time to grow, it can eventually grow down into the skin, ultimately reach the blood and lymphatic vessels and spread around the body, causing a life-threatening illness. Therefore, the goal is to detect melanoma early, when it is still on the surface of the skin. Melanoma can occur anywhere on the skin. Even in places not directly exposed to sun. However, it is most common on the backs of men and the legs of women. Melanoma is usually brown or black colored, but sometimes, though rare, may be red, skin colored, or white. Melanoma may also arise from a pre-existing mole, or appear on previously normal appearing skin. Melanomas slowly get larger; therefore, growing, changing, or irregular lesions should arouse suspicion.

When looking at a spot on the skin, it is helpful to apply the ABCDE rules to decide if it is suspicious.

The best treatment is early detection. A quick look from the trained eye of a dermatologist can confirm whether or not a lesion is suspicious for melanoma. If so, the next step is to perform a biopsy. The area is made numb, and a portion or the entire lesion is removed for examination under the microscope. This simple, quick procedure is performed in the dermatologist’s office. If a melanoma is detected, treatment is guided by how deep in the skin the melanoma is.

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. Early melanoma limited to the outermost layer of the skin (the epidermis) is known as melanoma in situ (in place), and simple surgical removal produces virtually a 100% cure rate. However, if left untreated, the melanoma grows deeper in the skin. The deeper it goes, the more likely it is to reach a blood vessel or lymphatic channel. If it enters these vessels, it can spread away from the skin, producing a life-threatening situation. When a biopsy is performed and melanoma is detected, the depth of invasion into the skin will be measured and reported by a dermatopathologist. This will guide treatment.

Deeper melanomas are more likely to spread. If a melanoma does spread, it typically spreads first to the lymph nodes. The lymph nodes are part of the lymphatic system, a series of vessels throughout the body much like blood vessels that are responsible for cleaning the body’s tissues. These vessels drain to local swellings known as lymph nodes, located at a variety of spots around the body. Different lymph nodes serve different parts of the body. If a melanoma did spread, it may be possible to find it at the lymph node before it goes any further. A procedure called a sentinel lymph node biopsy is a way of identifying and testing the first lymph node that drains the area the melanoma was located at. The decision on whether to perform a sentinel lymph node biopsy is based on how deep the melanoma is in the skin, and in turn, how likely it is to have spread.

Childhood and adolescent exposure seem to be the most damaging, so protecting young people is very important. Common sense dictates protection. Avoid sun exposure from 10:00 a.m. through 4:00 p.m., when the sun is the strongest. Wear a broad-spectrum sunscreen, one that blocks both types of ultraviolet light (UVA and UVB), and reapply frequently. Wear a hat, and clothing with a tight weave that will block ultraviolet light. Remember, a white cotton T-Shirt only blocks 50% of the suns rays. Avoid indoor tanning machines.

Early detection remains the best treatment. Therefore, perform a monthly self-exam, looking for irregular lesions that are growing and changing, and use the ABCDE rules. If you have an atypical mole, see a dermatologist immediately. Lastly, see a dermatologist at least once a year for a complete skin exam.