Note: The description below is provided for general information only and is not intended for self-diagnosis.
Moles, or nevi, are very common growths, which may be pigmented (brown) or skin-toned. They may occur at birth or later in life. Those present at birth are also known as congenital moles and often have one or more hairs emerging from them. Moles often start out flat and may slowly rise over the years.
When examining moles, care must be exercised to distinguish between benign moles and their malignant counterpart, malignant melanoma. Melanoma is a potentially very dangerous skin cancer, especially if not caught early in its evolution. Though some melanomas may arise within existing moles, others appear on previously unaffected skin.
Over the years, several criteria have been developed to attempt to separate moles from melanoma. Though such a separation may occasionally be difficult even for experts in the field, these criteria, also known as “ABCDE’s”, provide useful guidelines to try to determine which lesions should be monitored more closely or, possibly, biopsied for microscopic examination.
“A” stands for asymmetry. Unlike benign moles, melanomas often exhibit asymmetry; that is, one side of the lesion does not look like the other.
“B” stands for borders. Melanomas frequently have irregular or jagged borders, while moles typically present with sharp, rounded borders.
“C” stands for color. Most benign moles are either colorless (skin-toned) or contain only one color. In addition, black or very dark brown color, especially when compared to other moles on the body, should raise a suspicion of a possible malignancy. Beware, however, that some melanomas, the so-called “amelanotic melanomas”, are also skin-toned or reddish, with no conspicuous brown or black pigment. Though these cases are difficult to diagnose clinically, criterion “E” below usually still applies to amelanotic melanomas.
“D” stands for diameter. Benign moles are often smaller, most commonly less than 6 millimeters in diameter (the size of a pencil eraser). This, however, is not always true, as some congenital nevi may be larger than 6 millimeters, while melanomas may start off quite small. Nonetheless, a larger lesion size, especially when a new lesion is noted, should cause suspicion.
“E” stands for evolving, or changing. This is probably the most important criterion, as melanomas constantly continue to evolve – that is, increase in size or charge in color – whereas their benign counterparts should typically remain the same over time. In addition, the appearance of new moles should raise suspicion, especially in anyone over 40 years of age.
Additional suspicious characteristics may include bleeding or other symptoms arising within moles and a white halo-like rim appearing around a pigmented lesion. The latter occurrence may also be benign, as in the so-called “halo nevus”, though professional examination by a dermatologist is essential.
While these criteria are useful, they are intended as guidelines only. Thus, any suspected pigmented (or, occasionally, skin-toned) lesion should be brought to the attention of a dermatologist, such as Dr. Berlin, who will then determine whether further investigation is necessary.