Learn about moles (nevi), what causes them, whether they put you at increased risk of skin cancer and how to check a mole for signs of skin cancer.
Moles (nevi) are a common type of skin growth. They often appear as small, dark brown spots and are caused by clusters of pigment-forming cells (melanocytes). Most people have 10 to 40 moles that appear during childhood and adolescence and may change in appearance or fade over time.
Most moles are harmless. Rarely, they become cancerous. Being aware of changes in your moles and other pigmented patches is important to detecting skin cancer, especially malignant melanoma.
Moles are usually harmless. They may contain hairs or become raised or wrinkled. Talk to your doctor about any change in the color or size of a mole or if itching, pain, bleeding or inflammation develops.
The typical mole is a small brown spot. But moles come in different colors, shapes and sizes:
Moles can develop anywhere on your body, including your scalp, armpits, under your nails, and between your fingers and toes. Most people have 10 to 40 moles. Many of these develop by age 50. Moles may change or fade away over time. With hormonal changes in adolescence and pregnancy, they may become darker and larger.
Clusters of brown spots around the eyes, cheeks and nose are sometimes called flesh moles, but they are actually dermatoses papulosa nigra — a type of seborrheic keratosis, not clusters of pigment-forming cells (nevi). Dermatoses papulosa nigra are more common among Black women. Flesh moles don't carry a risk of melanoma, but they can be treated if you consider them a cosmetic concern.
A mole may be a sign of skin cancer if it has irregular borders or an asymmetrical shape or if it changes in color, shape, size or height. This ABCDE guide can help you remember what to watch for:
Cancerous (malignant) moles vary greatly in appearance. Some may show all of the changes listed above. Others may have only one or two unusual characteristics.
Make an appointment with your doctor if a mole looks unusual, grows or otherwise changes.
Moles are caused when cells in the skin called melanocytes grow in clusters. Melanocytes are generally distributed throughout the skin. They produce melanin, the natural pigment that gives skin its color.
Melanin is a natural pigment that gives your skin its color. It's produced in cells called melanocytes.
Melanoma is the main complication of moles. Some people have higher-than-average risk of their moles becoming cancerous and developing into melanoma. Factors that increase melanoma risk include:
The following measures can help limit the development of moles and the main complication of moles — melanoma.
Become familiar with the location and pattern of your moles. Regularly examine your skin to look for changes that may signal melanoma. Do self-exams of the skin once a month. With the help of mirrors, do a head-to-toe check, including your scalp, palms and fingernails, armpits, chest, legs, and feet, including the soles and the spaces between the toes. Also check the genital area and between the buttocks.
Talk with your doctor about your risk factors for melanoma and whether you need a professional skin exam on a routine basis.
Take measures to protect your skin from ultraviolet (UV) radiation, such as from the sun or tanning beds. UV radiation has been linked to increased melanoma risk. And children who haven't been protected from sun exposure tend to develop more moles.
Your doctor can diagnose moles by looking at your skin. During a skin exam, your doctor inspects your skin from head to toe. If your doctor suspects that a mole may be cancerous, it is removed and sent to a lab for examination under a microscope (biopsy).
You might choose to make a skin exam a regular part of your preventive medical care. Talk with your doctor about a schedule that's appropriate for you.
Most moles don't need treatment. If you're self-conscious about a mole, you could try makeup to help conceal it. If you have a hair growing from a mole, you might try clipping it close to the skin's surface or plucking it. Anytime you cut or irritate a mole, keep the area clean. See your doctor if the mole doesn't heal.
You might also talk with your dermatologist about surgically removing a mole if it bothers you or if you notice suspicious changes in it. Mole removal takes only a short time and is usually done on an outpatient basis. Your doctor numbs the area around the mole and cuts it out, along with a margin of healthy skin if necessary. The procedure may leave a permanent scar. People with Black skin are at increased risk of other surgical side effects, such as pigmentary changes at the incision site and keloid scars.
If you notice that a mole has grown back, see your doctor promptly.
If you have a mole that concerns you, your family doctor can usually let you know if it's normal or needs further investigation. He or she may then refer you to a doctor who specializes in skin disorders (dermatologist) for diagnosis and treatment.
It's a good idea to arrive for your appointment well prepared. Here's some information to help you get ready.
For moles, some basic questions to ask your doctor include:
In addition to the questions that you've prepared, don't hesitate to ask questions during your appointment.
Your doctor is likely to ask you a number of questions, such as: