According to the Skin Cancer Foundation, as a general rule, to spot either melanomas or non-melanoma skin cancers (such as basal cell carcinoma and squamous cell carcinoma), take note of any new moles or growths, and any existing growths that begin to grow or change significantly in any other way. Lesions that change, itch, bleed, or don't heal are also alarm signals.
It is so vital to catch melanoma, the deadliest form of skin cancer, early that physicians have developed two specific strategies for early recognition of the disease: the ABCDEs and the Ugly Duckling sign.
This benign mole 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 malignant mole, 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 your pencil tip (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, see a doctor. Any change — in size, shape, color, elevation, or another trait, or any new symptom such as bleeding, itching or crusting — points to danger.