Moles

Moles are common skin growths caused by a cluster of pigmented cells. Moles can occur in a range of colors, but are most often small, brown spots. Although most moles are harmless, they can sometimes develop into cancer and should be closely monitored for changes.

Moles often appear in childhood and can continue to develop into adulthood. Most people have between 10 and 40 moles.

Types of moles

Moles can be classified as regular, irregular, or cancerous. Regular moles are benign and usually symmetrical with uniform color. They may be flat or raised.

Irregular moles, known medically as dysplastic nevi, are usually asymmetrical with irregular borders and multiple or dark colors. They are most often flat. Having more than 20 irregular moles can increase your risk of skin cancer.

Moles and skin cancer

Regular self exams and annual professional checkups are recommended to detect any changes in moles that could indicate cancerous cell growth. Not all skin cancer develops from pre-existing moles, so watch for new skin growths and other changes as well.

When examining moles, use the ABCDE method to identify features that could indicate cancer:

• Asymmetry: the mole is oddly shaped, or one half is different from the other.
• Borders: the mole has irregular or uneven borders.
• Color: the color of the mole changes from one area to another. A mixture of colors may appear within one growth.
• Diameter: malignant moles are usually larger than 6mm, or the size of a pencil eraser.
• Evolving: the mole changes over time. It may grow larger, change color or shape, or develop other symptoms, such as itching or bleeding.

If you have a mole that starts to grow, itch, or bleed, have it examined by your dermatologist.

Mole removal

If you have a mole that appears suspicious, your doctor will likely take a sample of tissue from the mole and examine it for cancer. If cancerous cells are found, the entire mole and some of the surrounding tissue will be removed.

Although regular moles do not need to be treated, many people elect to have them removed for aesthetic reasons. Regular moles can be removed through surgical cutting or shaving.