Melanocytes are cells in the skin that contain a pigment called melanin, which is the dark color also found in the hair and in the eye. These cells live between the epidermis and dermis — the top two layers of the skin. As people age, or get lots of sun, the number of melanocytes in the skin may increase, forming dark spots or moles. Most melanomas are benign, which means they are not harmful in any way. In some cases, however, these dark spots or moles can develop into spots that are malignant, which means they are a sign of a serious form of skin cancer.
The development of malignant melanomas has been linked to overexposing the skin to the sun. In fact, some medical professionals believe that receiving just one serious sunburn can double a person’s likelihood of developing malignant melanomas. In addition, two serious sunburns in a person’s childhood or adolescent years can triple the likelihood of developing them.
Malignant melanomas may appear anywhere on a person’s body, including hard to see areas such as in the nail bed, on the scalp, and inside the mouth or nose. Regardless of the location, there are several signs a person should look for when identifying them. The most common technique for inspecting melanomas to determine whether they are benign or malignant is to follow the ABCDs rule.
The A in the ABCDs rule stands for asymmetry. Benign melanomas are symmetrical, so both sides would look the same if the spot was cut in half. Those that are asymmetrical, or that do not have matching halves, are potentially malignant.
The B in the ABCDs rule is the border. Malignant melanomas may have an uneven border, or they may have notched edges or a scalloped look. Those that are benign, on the other hand, have smooth and even borders.
The C represents the color. Benign melanomas are generally one shade of brown throughout. Malignant ones, on the other hand, may have a variety of brown, tan, and black coloring. As they become worse, they may change to white, red, or even blue.
The D of the ABCDs stands for diameter. Malignant melanomas usually grow to a larger size than those that are benign. Any spot that is the size of a pencil eraser or larger is potentially malignant.
Malignant melanomas may show one or several of the signs covered in the ABCDs rule. When caught early, they can be removed, and the patient can recover completely. If allowed to progress, however, the cancer may move to other areas of the body and become a serious, life-threatening disease.