When a Mole is More than a Mole

By Ayelet Mizrachi-Jonisch, MD FAADDermatology 

Normal moles are common small brown spots or growths on the skin that appear in the first few decades of life. They can be either flat or elevated and are generally round and regularly shaped. Many are caused by sun exposure and most moles are harmless. However, moles can become cancerous. Monitoring moles and other pigmented patches is an important step in detecting skin cancer, especially malignant melanoma.

Melanoma is one of the deadliest forms of skin cancer.  Moles that are melanoma most often appear as asymmetrical, irregularly bordered, multicolored or tan/brown or as a growth that continues to increase in size over time. They may begin as a flat spot and become more elevated. In rare instances, the moles may be amelanotic, in other words, the mole does not have any of skin pigment (melanin).  In these cases, the mole may be pink, red, or normal skin color, making it harder to recognize as a melanoma.

Sometimes it can be hard to tell the difference between an atypical mole and an early melanoma.  This ABCDE guide can help you determine if a mole or a spot may indicate melanoma or other skin cancers:

Asymmetry: Unlike common moles, atypical moles are often asymmetrical:  A line drawn through the middle would not create matching halves.

Border: While common moles usually have regular, sharp, well-defined borders, the borders of atypical moles tend to be irregular and/or hazy — the mole gradually fades into the surrounding skin.

Color: Common moles are most often uniformly tan, brown or flesh-colored, but atypical moles have varied, irregular color with subtle, haphazard areas of tan, brown, dark brown, red, blue or black.

Diameter: Atypical moles are generally larger than 6 mm (¼ inch), the size of a pencil eraser, but may be smaller.

Evolution: Enlargement of or any other notable change in a previously stable mole, or the appearance of a new mole after age 40, should raise suspicion.

The degree of atypical features in the mole can determine whether it is harmless, or at moderate or high risk of becoming a melanoma. Dermatologists examine such moles with a dermoscope, a handheld magnifying device that allows visualization of internal skin structures and colors not seen by the naked eye. The dermatologist may also opt to remove the entire mole or a portion of it for examination in a lab.

Certain factors can be clear warning signs that an atypical mole is actually a melanoma or in danger of becoming a melanoma. These include itching, pain, elevation, bleeding, crusting, oozing, swelling, persisting open sores, bluish-black color and other features. If you or a loved one has any of these warning signs, consult a dermatologist immediately.

Watch for changes

Become familiar with the location and pattern of your moles. Regularly examine your skin to look for changes that may signal melanoma, especially if you have a family history of melanoma. With the help of mirrors, do a head-to-toe check, including your scalp, palms and fingernails, armpits, chest, legs, and your feet, including the soles and the spaces between the toes. Also check your genital area and between your buttocks.

Protect your skin

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. Children who haven’t been protected from sun exposure tend to develop more moles. Avoid peak sun times between 10 am and 4 pm. Use sunscreen year-round.  Cover up and get in the habit of wearing sunglasses, broad-brimmed hats, long sleeves and other protective clothing that can help you avoid damaging UV rays.

Talk with your doctor about your risk factors for melanoma and whether you need a professional skin exam on a routine basis.

skin cancer