When a Mole Isn't Just a Mole

Q:  I have a not-so-small mole on my back and it's been there for a while (maybe even for years, because it's hard for me to see it). A friend of mine says I should get it checked out, but I can't get in to see my regular doctor for several months. Can it wait that long? I don't want to take up my doctor's time if it's just a mole.

A:  The reason for getting a mole "checked out" is to confirm that it isn't melanoma, one of the most common types of cancer. Melanoma occurs when melanocytes, the pigment cells in the skin, become malignant. Although the disease affects people of all ages, the chance of developing it increases as we get older.

In men, melanoma is often found on the trunk of the body, or on the head and neck. In women, it often develops on the lower legs. Melanoma is rare in people who have dark skin, but when it does develop in dark-skinned people, it tends to show up under the fingernails or toenails, or on the palms or soles.

Often, the first sign of melanoma is a change in the size, shape, color, or feel of an existing mole. Most melanomas have a black or blue-black area. Melanoma also may appear as a new mole; it may be black or just look abnormal.

Melanoma can be cured if it is diagnosed and treated when the tumor is thin and has not deeply invaded the skin. However, if a melanoma is not removed at its early stages, cancer cells may grow downward from the skin surface and invade healthy tissue. When a melanoma becomes thick and deep, the disease often spreads and is difficult to control.

When melanoma spreads, cancer cells may show up in nearby lymph nodes. If the cancer has reached the lymph nodes, it may mean that cancer cells have spread to other parts of the body such as the liver, lungs, or brain.

Surgery is the usual treatment for melanoma. The surgeon removes the tumor and some normal tissue around it. This procedure reduces the chance that cancer cells will be left in the area. The width and depth of surrounding skin that needs to be removed depends on the thickness of the melanoma and how deeply it has invaded the skin.

The great majority of moles are simply moles, but there are features that make a mole suspicious for melanoma. These features can be remembered by the initials A, B, C, D and E:

• Asymmetry,
• Border irregularities,
• Color changes within the mole,
• Diameter large (greater than 6-7 mm), and
• Enlargement with time.

If your mole has any of these features or if you are at high risk for melanoma, such as having melanoma in your family or a suppressed immune system, you should consult with your doctor. When calling about the appointment, specifically tell the nurse the reason for your visit. Melanomas can be easily cured if they are caught early enough.

This article includes information from the National Cancer Institute.

Julie L. Mitchell, MD, MS, is an Assistant Professor of Medicine at the Medical College of Wisconsin. She practices internal medicine at the Froedtert & Medical College General Internal Medicine Clinic - East. Her column also appears in the Milwaukee Journal-Sentinel.