Mole is the common name for a melanocytic nevus (plural: nevi). Moles are very common, and adults with fair skin may have as many as 10-40 on their skin. Most moles appear during childhood or adolescence and can grow as the child grows. If there is a new mole that appears during adulthood or if an existing mole changes, it may be an early sign of melanoma and a close examination by a dermatologist should be scheduled right away. New moles in childhood or adolescence are normal, but the following are reasons to be checked by a dermatologist:
- Changing mole
- Dome-shaped mole, jagged borders, or containing different colors
- Bleeding mole
- Many moles
- Large or giant mole, even if present at birth
Checking moles regularly at home between dermatology visits is important, and checking moles in childhood can create a healthy, lifelong habit.
In order to help determine features of a mole that might be concerning for a melanoma, there is a mnemonic called the “ABCDEs of melanoma.” Any of the following features should prompt an urgent examination by a dermatologist:
- Asymmetry: one half is unlike the other half
- Border: an irregular, scalloped, or poorly defined border
- Color: variations of tan, brown, black, and sometimes white, red, or blue
- Diameter: melanomas are usually greater than 6mm (size of a pencil eraser)
- Evolving: anything that looks like a mole but is changing while others aren’t
Most moles are considered benign (not cancerous), but there are some that are called atypical nevi. An atypical nevus may be an early melanoma, and having multiple atypical nevi may mean that a person’s risk for having a melanoma is higher than average. Moles that appear atypical to the eye of a dermatologist will likely be checked using a biopsy and examined under the microscope by a pathologist. Shave technique, punch technique, or excision may be used to take the biopsy. If biopsy shows that a mole is severely atypical, surgical excision with a margin of normal skin around the area of the biopsy will be recommended. If the biopsy shows that it is a melanoma, a larger margin will be necessary and further treatment may also be necessary depending on specific information learned from the biopsy.
Moles should not be removed at home. If you have numerous moles, your dermatologist may instruct you to use a camera at home along with your self-exams in order to keep a “mole map” for comparison to detect changes over time. Protect your skin from the sun and wear sunscreen when outside.