By the time they reach adulthood, most people have at least one mole, and usually many more. Moles are generally harmless. These small, colored spots are usually nothing to worry about unless they change size, texture, shape, or color.
Everyone has moles, which are growths on the skin that are usually brown or black but can sometimes be pink or tan.
Moles can be present at birth, or acquired later in life.
You need to check your moles monthly, looking for any changes, as this may indicate the presence of cancer.
Seek advice from your healthcare provider, who will diagnose your condition and suggest treatment.
These changes can happen quickly or gradually and can be an early sign of melanoma or another type of skin cancer. Therefore, no matter your age, it's important to be proactive about your health. Regularly checking your skin and moles is one way to stay on top of any potential concerns. Knowing what to look for allows you to catch any growths or changes early and address them quickly.
What are moles?
Moles are growths on the skin that are usually brown or black but can sometimes be pink or tan. They can occur anywhere on the body, alone or in groups. They're usually round or oval and under five millimetres wide. Moles can be flat or raised, smooth or textured like a wart, and some may have hairs growing from them.
Moles are clusters of pigmented cells called melanocytes. Normally these cells grow evenly throughout the skin, giving it its color. However, moles develop when these cells gather together rather than spread out.
Most moles are congenital, meaning that a person is born with them. However, people can also develop new moles, particularly during puberty or pregnancy. Those who spend a lot of time in the sun or use tanning beds are also more likely to develop new moles.
What are the different types of moles?
Doctors classify moles into three categories:
- Congenital moles – These are present at birth. Only large moles over 20mm in size have a significant risk of turning into skin cancer.
- Acquired moles – Most moles fit into this category and are acquired throughout life. They are usually smaller than five mm, have even pigmentation, and a symmetrical border. The vast majority of these moles do not develop into cancer.
- Atypical mole – These moles are also called dysplastic nevi. They're larger than regular moles and have irregular features, such as an uneven border or multiple colors. They can appear anywhere on the body but more commonly in areas exposed to ultraviolet light, such as the neck or back. People may have several atypical moles, and they may also have numerous normal moles.
What to look for when checking your moles?
People should check their moles regularly to ensure no suspicious changes. Even if you have no moles, you should still examine your skin as moles can develop at any time.
You should review your moles monthly by using a full-length mirror and a hand mirror to help you check areas that are not easy to see. Then, working down from the head, check all areas of the skin, including the soles of the feet, backs of the knees, fingers, toes, and groin. It's also important to check the scalp, neck, and back as these areas often have the most sun exposure.
After several months of regular monitoring, you'll become familiar with your moles’ appearance. You can also take photos and include a ruler in the shot so that it's easy to compare with previous months and spot any changes.
You can use the ABCDE technique while self-checking moles:
- Asymmetry – Do both sides of the mole match, or is it asymmetrical?
- Border – Are the borders or edges irregular, ragged, notched, or blurred?
- Color – Is the color uneven or blotchy?
- Diameter – Is the diameter getting larger over time?
- Evolving – Is the mole changing and evolving and appears different from your other moles?
The 'Ugly Duckling' sign is something else you should be aware of. It's the assumption that normal moles usually resemble each other, while cancerous moles are obvious in comparison – like an ugly duckling.
It's particularly important to check your skin and moles if:
- You have pale skin.
- You have multiple moles.
- You have close family members with many moles, atypical moles, or a history of skin cancer.
When to see a doctor about your moles
Usually, moles are benign or non-cancerous and nothing to worry about. But it's a good idea to have your doctor examine any new moles or existing moles that show any signs of change as these could be signs of skin cancer.
Other times you should see your doctor include:
- If there’s itchiness, redness, pain, or bleeding around a mole.
- If a mole appears after age 25.
- If you have more than 50 moles.
- If you have moles on your scalp, groin, or under your nails.
- If you have fair skin and moles.
What happens if the doctor thinks a mole is suspicious?
If your doctor thinks a mole may be cancerous, they'll take a small sample of tissue from it. They then send this biopsy sample to a laboratory for testing. In some cases, the doctor uses a special needle to take the tissue sample. This is called fine-needle aspiration biopsy.
The laboratory then examines the cells from the mole under a microscope to look for abnormal changes associated with skin cancer.
Should the biopsy show skin cancer, your doctor can discuss treatment options with you. Local treatment options include:
- Freezing. Your doctor can use liquid nitrogen to freeze away the mole.
- Excisional surgery. This involves removing the cancerous tissue and a surrounding margin of healthy skin.
- Mohs surgery. An option for areas where it's important to conserve skin, such as on the nose. The skin is removed layer by layer, and each is examined under a microscope until no abnormal cells remain.
- Curettage combined with electrodesiccation or cryotherapy. Curettage involves scraping away the cancerous tissue with a sharp instrument. Next, any remaining cancer cells are destroyed with an electric needle (electrodesiccation) or extreme cold (cryotherapy).
In some cases, doctors may recommend other treatments, including:
- Radiation therapy.
- Photodynamic therapy.
- Biological therapy.
Can moles be prevented?
Moles can't be prevented, but you can take steps to prevent skin cancer or catch it early by:
- Limiting exposure to the sun.
- Avoiding tanning beds.
- Wearing sunscreen daily.
- Examining your moles regularly.