Melanoma is the most dangerous form of skin cancer, these cancerous growths develop when unrepaired DNA damage to skin cells (most often caused by ultraviolet radiation from sunshine or tanning beds) triggers mutations (genetic defects) that lead the skin cells to multiply rapidly and form malignant tumors. These tumors originate in the pigment-producing melanocytes in the basal layer of the epidermis. Melanomas often resemble moles; some develop from moles. The majority of melanomas are black or brown, but they can also be skin-colored, pink, red, purple, blue or white. Melanoma is caused mainly by intense, occasional UV exposure (frequently leading to sunburn), especially in those who are genetically predisposed to the disease. Melanoma kills an estimated 10,130 people in the US annually.
If melanoma is recognized and treated early, it is almost always curable, but if it is not, the cancer can advance and spread to other parts of the body, where it becomes hard to treat and can be fatal. While it is not the most common of the skin cancers, it causes the most deaths. In 2016, an estimated 76,380 of these will be invasive melanomas, with about 46,870 in males and 29,510 in women.
The ABCDEs of Moles
Moles, brown spots and growths on the skin are usually harmless — but not always. Anyone who has more than 100 moles is at greater risk for melanoma. The first signs can appear in one or more atypical moles. That’s why it’s so important to get to know your skin very well and to recognize any changes in the moles on your body. Look for the ABCDE signs of melanoma, and if you see one or more, make an appointment with a provider immediately.
The benign mole, left, is not asymmetrical. If you draw a line through the middle, the two sides will match, meaning it is symmetrical. If you draw a line through the mole on the right, the two halves will not match, meaning it is asymmetrical, a warning sign for melanoma.
A benign mole has smooth, even borders, unlike melanomas. The borders of an early melanoma tend to be uneven. The edges may be scalloped or notched.
Most benign moles are all one color — often a single shade of brown. Having a variety of colors is another warning signal. A number of different shades of brown, tan or black could appear. A melanoma may also become red, white or blue.
Benign moles usually have a smaller diameter than malignant ones. Melanomas usually are larger in diameter than the eraser on a pencil (¼ inch or 6mm), but they may sometimes be smaller when first detected.
Common, benign moles look the same over time. Be on the alert when a mole starts to evolve or change in any way. When a mole is evolving, see a provider. Any change in size, shape, color, elevation, or another trait, or any new symptom such as bleeding, itching or crusting can point to danger.