An important subject is whether flat, tan or brown spots on your skin are freckles or moles. And it’s not just an academic question. It’s actually vitally important to your health because freckles are of “only” cosmetic importance, yet moles are what most deadly melanoma cancers come from. So let’s discuss the differences so you can identify yours.
So freckles. They’re harmless, usually first appear in childhood, seasonally darken in the spring and summer from sun exposure, even with effective sunscreen use, and they lighten in the fall and winter. Under the microscope, they consist of normal appearing melanocytes, which are the cells that make your brown pigment called melanin. While they’re tan or brown, although more tan than brown, they tend to be lighter in color than moles, but more importantly, are usually only one shade or hue, not different shades of brown. And they are mostly on areas of your skin that are most exposed to the sun… like your face, upper chest and back, and the top of your forearms.
Moles, on the other hand, occur anywhere on your body, even in areas that have never seen the sun. They're often more than one shade of tan or brown, change very slowly over months and years but not from short term or seasonal sun exposure. And often, as they become abnormal and precancerous, they develop irregular borders. At this stage, the mole has probably become precancerous and is called a “dysplastic nevus.” It’s still not a cancer, but is already changing and not looking normal. Even at this stage it still only has a 25% chance of becoming melanoma. But since we, as experts in dermatologic diagnosis can’t distinguish between the 25% that become melanoma and the 75% that don’t, I recommend removal of all dysplastic nevi. As another note, a mole won’t turn from normal to precancerous, nor cancer over night. It's a very slow process.
So since it’s so important to recognize the difference between a freckle and a mole, make sure you get a complete exam by a dermatologist annually for the early detection and treatment of precancerous moles and skin cancer, even if you think your spots are all just freckles.