Moles - nevi
Moles come in a wide variety of colors, shapes and sizes. Moles are usually harmless collections of pigmented cells called melanocytes on your skin. They can appear alone or in multiples. Moles are also called nevi; a single mole is a nevus. Most moles are present on the torso, but they are also commonly found on your face, arms and legs. Moles can be present in more obscure locations as well - including on your scalp, under your nails, in your armpits and around your genitals.
Most of us have from 10 to 40 moles. The number of moles you have may constantly change. New moles may appear up through your midadult years, but most appear by age 20. Some moles disappear with advancing age.
It's especially important to become familiar with the moles on your skin because, in rare cases, they can become cancerous. Monitoring your moles and other pigmented patches, such as freckles and age or liver spots, is an important first step in reducing your risk of skin cancer - especially malignant melanoma, which may begin in or near a mole or other dark spot on the skin. Melanoma also can arise in areas of normal pigmentation.
Signs and symptoms
Moles come in a wide variety of colors, shapes and sizes. They can be flesh-colored, brown, blue or black spots that vary in shape from oval to round. They can be as small as a pinhead or large enough to cover an entire limb. Moles that are larger than 8 inches in diameter and present at birth are a special problem. They may need to be removed to avoid the risk of cancer.
The surface of a mole can be smooth or wrinkled, flat or raised. Over your lifetime, some of your moles are likely to change. With exposure to sun, they may darken. They also may start out flat and brown in color and later become slightly raised and lighter in color. Some may become raised enough that they form a small stalk and are eventually rubbed off. Others may just disappear.
There are certain times in your life when moles may be more apt to change. During adolescence, for example, moles may darken and become larger. During pregnancy, women may develop numerous and darker moles.
Moles have no known purpose, and scientists don't know why they develop. Most moles are harmless and don't require special care. If a mole is irritated or unattractive, however, you may want to have it removed. All moles that are removed should be examined under a microscope because doctors can't always tell if moles are precancerous or cancerous just by the way they look on your skin. In all cases, you need to monitor your own moles for changes in size, shape, color, texture and sensation that may indicate a problem.
Several types of moles have a higher than average risk of becoming cancerous. They include:
If you're fair-skinned, blue-eyed, freckled and have light-colored hair, you're at particularly high risk of skin cancer of all kinds, not just melanoma. Avoid overexposure to sunlight and protect your skin from sunburn and blistering. The majority of lifetime sun exposure for most people occurs before age 20. Be sure to begin sun protection habits in early childhood for your children and grandchildren, and maintain these habits yourself at all ages. Avoid strong sun exposure, wear protective clothing and use sunscreens.
When to seek medical advice
If a new mole appears in adulthood, past age 20, see your doctor. These signs and symptoms may indicate a medical concern:
If you're concerned about any mole, see your doctor or ask for a referral to a dermatologist.
Screening and diagnosis
You may choose to make a skin examination a regular part of your preventive medical care. Talk to your doctor about a schedule that's appropriate for you. A general guideline is every three years for people ages 20 to 39, and annually for people age 40 or older.
Your doctor will examine your skin from head to toe, including your scalp, your palms, the soles of your feet and the skin between your buttocks. If your doctor suspects that a mole may be cancerous, he or she may take a sample of the tissue (biopsy) and submit the biopsy for microscopic examination.
If your doctor takes a tissue sample of the mole and finds it to be cancerous, the entire mole and a margin of normal tissue around it needs to be removed. Usually a mole that has been removed won't reappear. If it does, see your doctor promptly.
Treatment of most moles usually isn't necessary. For cosmetic reasons, a mole can be removed in several ways:
These procedures are usually performed in the office of your doctor or dermatologist and take only a short time.
The best way to catch potential problems at an early stage is to become familiar with the location and the pattern of your moles. Examine your skin carefully on a regular basis — monthly if you have a family history of melanoma, and at least every three months otherwise — to detect early skin changes that may signal melanoma, the most serious form of skin cancer.
Remember to check areas that aren't exposed to sunlight, including your scalp, armpits, feet (the soles and between the toes), genital area and, if you're a woman, the skin underneath your breasts. If necessary, use a hand-held mirror along with a wall mirror to scan hard-to-see places such as your back. People with dysplastic nevi are at greater risk of developing malignant melanoma and may want to consider having a dermatologist check their moles on a regular basis.
To detect melanomas or other skin cancers, use the following A-B-C-D skin self-examination guide, adapted from the American Academy of Dermatology:
In addition to periodically checking your moles to note any changes, you can take protective measures to help care for your moles. First and foremost, avoid sun exposure, particularly from 10 a.m. to 4 p.m., when ultraviolet rays are most intense. Apply sunscreen with a sun protection factor (SPF) of at least 15 to minimize the risk of skin cancer. Broad-brimmed hats, long sleeves and other protective clothing also can help you avoid damaging sun rays. These measures are important at every age.
Some sunscreens contain substances that block both types of ultraviolet rays responsible for superficial skin damage and skin cancer, ultraviolet A (UVA) and ultraviolet B (UVB). Choose sunscreens with avobenzone, titanium dioxide, and transparent or microdispersed zinc oxide listed on the ingredient label.
If you have a mole that's unattractive, you may choose to cover it up using makeup designed to conceal blemishes and moles. If you have a hair growing from a mole, it may be possible to clip it close to the skin's surface. Dermatologists also can permanently remove hair from moles. If you have a mole in a beard, you may want to have it removed by your doctor because shaving over it repeatedly may cause irritation. You may also want to have moles removed from other parts of your body that are vulnerable to trauma and friction.
Anytime you cut or irritate a mole, be sure to keep the area clean. See your doctor if the mole doesn't heal.