Is It a Mole or Melanoma? How to Spot the Signs of Skin Cancer

Content medically reviewed by Dr. Dong Joo Daniel Kim, MD, FAAD

Wondering whether a spot on your skin is a mole or some type of skin cancer? It’s a common question that’s worth investigating. Knowing the signs of melanoma can be lifesaving.

Protecting your skin is a year-round necessity. Potent ultraviolet (UV) rays penetrate down to earth on warm and cold days alike, even when it’s cloudy.Learn about the signs of melanoma and how you can reduce your risk with basic sun safety.

The Facts About Melanoma

Melanoma develops in the skin cells that produce melanin, which gives skin its color. Other types of skin cancer can develop in keratinocytes within the squamous or basal layers of the skin.

The American Cancer Society estimates nearly 105,000 new melanomas will be diagnosed in the United States in 2025. While this type of skin cancer is less common, it’s often more dangerous because it can quickly spread to other parts of the body.

“Melanoma detected in an early stage, before it spreads, is much easier to treat,” said Dr. Dong Joo Daniel Kim, board-certified dermatologist at Essentia Health.

There are four types of melanoma –

• Superficial spreading melanoma is most likely to develop on the torso in men and the legs in women. Its name reflects the fact it tends to grow on the skin’s surface for a while before spreading deeper.
• Nodular melanoma grows deep into the skin and is most often found on the torso, legs, and arms. It may also develop on the scalp in older men.
• Lentigo maligna most often grows on sun-damaged skin on the face, ears, arms, or upper torso.
• Acral lentiginous melanoma is the most common type of melanoma in people of color and often develops in hidden places such as under nails, on the palms of the hands, or on the soles of the feet.

Of the four types, superficial spreading melanoma is most common, accounting for around 70% of melanomas.

Spotting the Signs of Melanoma

It’s a good idea to regularly take a close look at your skin, checking for anything abnormal. The acronym ABCDE can help you remember what to look for –

• Asymmetry, where one half of the spot looks different than the other
• Borders that are irregular
• Color varying from one part of the spot to another
• Diameter larger than a pencil eraser
• Evolving appearance

Melanomas come in a variety of colors, including tan, black, brown, white, pink, red, or blue. They can even be colorless—melanomas can be amelanotic, meaning they’re the same color as your skin.

How can you tell the difference between a melanoma and a regular mole? For one, if you had the mole for a while and it isn’t changing, it’s probably a regular or “common” mole, although if there are any doubts it is always worth getting it evaluated. According to the Skin Cancer Foundation, up to 80% of melanomas develop in normal skin, making it less common for cancer cells to develop in an existing mole.

The ABCDE identifiers listed above can help you determine whether a spot is a common mole or not. Normal moles are the opposite of what’s described—they’re symmetrical, have even borders, are usually a single color, are smaller than a pencil eraser, and don't change over time.

The so-called “ugly duckling” sign can also help you identify a skin spot in need of a provider’s attention. When you’re examining your skin, you’re looking for spots that stand out from others.

If you notice any of these signs of melanoma, check in with your primary care provider or a board-certified dermatologist, who can evaluate the spot for you.

5 Steps You Can Take to Protect Your Skin

Most cases of skin cancer, including melanoma, are caused by exposure to UV rays. Because of that, you can take steps to lower your risk. Start with these basics –

1. Make sunscreen a must. Before going outside, apply sunscreen with a sun protection factor (SPF) of at least 30 to all exposed skin year-round. Reapply at least every two hours while outdoors, or more often if you’re swimming or sweating. Sun-protective clothing can also shield your skin.
2. Seek the shade. While soaking up the sun may be a delight when we hit the warmer part of the year, limit your time in the sun. Whenever possible, perch yourself under an umbrella, an overhang, or a patio roof.
3. Just say no to tanning beds. There’s no such thing as a safe tan. Even a single session in a tanning bed can increase the risk of melanoma significantly. If you still want bronzed skin, turn to an artificial tanning product or a spray tan.
4. Know your risk factors. While anyone can develop melanoma, the risk is higher for those with lighter skin, hair, and eye color. Having a family history of melanoma or a personal history of skin cancer also increases your risk, as does having a medical condition that causes a weakened immune system. If you’re at an increased risk, take extra precautions to protect your skin.
5. Have regular skin checks. While you should be frequently checking your own skin, it’s also a good idea to have skin checkups with a board-certified dermatologist or another provider.

“During a skin check, your provider will take a close-up look at your entire body, including your scalp and the bottoms of your feet, examining it for any abnormalities,” Kim said. “If something abnormal is seen during a skin check, it may be removed for a biopsy, which examines for cancer cells.”