Melanoma lurks in larger skin lesions, NYU researchers find

Skin lesions that are about the size of a pencil eraser are more likely to be melanomas, a deadly form of skin cancer, than smaller moles, according to a new study led by NYU Langone Medical Center researchers.

In a new study published in the April issue of Archives of Dermatology, the NYU researchers confirm that an important warning sign of melanoma — moles that are larger than 6 millimeters, the size of a pencil eraser — is still valid. In recent years, some researchers have argued that strict adherence to this guideline may make clinicians miss smaller melanomas.

“Diameter is a reasonable guideline to pay attention to and we did not see any reason to change it,” says David Polsky, M.D., Ph.D., assistant professor of dermatology and associate director of the Pigmented Lesions Section in the Roland O. Perelman Department of Dermatology at NYU School of Medicine, who led the study.

“Lesions that are smaller than 6 millimeters are unlikely to be melanoma. New and changing lesions are the most concerning, and lesions that are multiple colors are especially suspicious,” says Dr. Polsky.

More than 20 years ago, NYU dermatologists developed a widely used rule, the ABCD acronym, for recognizing growths on the skin that could be early melanomas. They recently added the letter E to the list. The warning signs are: A for asymmetrical lesions; B, lesions with irregular borders; C, lesions with multiple colors; D, for lesions larger than 6 millimeters; and E for evolving lesions that change in size, color, shape or symptoms such as itching over time.