Are moles cancerous?
August 02, 2021
Medically Reviewed | Last reviewed by an MD Anderson Cancer Center medical professional on August 02, 2021
Almost everyone has at least one mole, and you may already regularly check your moles for signs of change.
That’s a good idea since a changing mole can mean that something has gone wrong in the cells and a cancer is forming.
So, does that mean that moles are cancerous? Or that you will get skin cancer if you have moles?
We talked to Saira George, M.D., a dermatologist at MD Anderson in Sugar Land, to find out.
What are moles?
Moles are clusters of melanocytes. These are the cells in our skin that give it color. These melanocytes are normally spread out between other skin cells. Their job is to transfer pigment, called melanin, to neighboring cells to help protect them from ultraviolet damage. When melanocytes grow as a cluster or group instead of spreading out, we call it a mole. It’s not clear exactly how or why our skin forms moles, but we think genetics and sun exposure may play a role.
Are moles cancerous?
Moles are not cancerous or dangerous. They are simply a group of normal melanocytes. But if their DNA gets damaged, it can cause them to turn cancerous. These cancerous growths of melanocytes are called melanoma. When the cancer cells in melanoma divide, they form a disorganized group or cluster that looks like a new or changing mole.
How do you tell the difference between normal moles and melanomas?
Moles usually form before you reach age 40, and they look somewhat similar. They are slow growing and don’t change quickly. The cancer cells in melanoma divide and grow abnormally, so a melanoma often looks like an “ugly duckling” mole. It will likely look different from any other brown spots on your skin, it may be new, and it may continue to change over time.
You can examine your moles using the ABCDEs guide for melanoma.
Melanomas are often asymmetrical. That means the two sides look different from each other. They often have borders that are blurry, scalloped or jagged. Melanomas also often have many colors or are haphazardly colored. You should also look at the size. A mole that is larger than 6 millimeters, or the size of a pencil eraser, is cause for concern. Talk with your doctor if you notice any of the ABCDEs of melanoma, or if you have a mole that is evolving or changing in size, shape or feeling.
What are the signs of other types of skin cancer?
Melanoma is a cancer of one type of cell in the skin, melanocytes. But your skin has other cells that can become cancerous. For example, skin cells called keratinocytes give rise to basal cell or squamous cell carcinoma. These cancers usually appear as suspicious pink or skin colored spots on the skin.
Along with checking the ABCDEs on your moles, you should also look for other skin irregularities. These could appear as a small, smooth, shiny, pale or waxy lump, a firm red lump that may bleed or crust, or a flat red spot that is rough, dry or scaly.
Should you get a regular screening exam for skin cancer?
Skin cancer screening is recommended for people who are at increased risk of skin cancer. This could be because of your family history, skin type, history of sun exposure, genetic syndromes, tanning bed use, a large number of moles or other factors.
But even if you’re not at high risk for skin cancer, it’s important to be aware of your skin. Talk to you doctor if you notice any changes that last for more than two weeks, or if you see something that concerns you. Early detection is the best chance for success against skin cancer, if changing moles or other skin changes turn out to be cancer.
Request an appointment at MD Anderson online or by calling 1-877-632-6789.
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Saira George, M.D.
Physician