ABCD Rules for Diagnosis of Melanoma Reviewed

“The American Academy of Dermatology Ad Hoc Task Force for the ABCDEs of Melanoma, chaired by Hensin Tsao, MD, PhD, reviewed the mnemonic for early detection of melanoma and determined it has strengths and weaknesses.

“The ABCDE mnemonic includes A = asymmetry, B = border, C = color, D = diameter and E = evolving. The individual ABCDE criteria display sensitivities of 57%, 57%, 65%, 90% and 84%, and specificities of 72%, 71%, 59%, 63% and 90%, respectively, when used by dermatologists for diagnosing melanoma.

“The reviewers specifically looked at the use of the diameter (D) criterion and whether it should be revised to include melanomas smaller than 6 mm. They reported that studies have found melanomas smaller than 6 mm ranged from 2.2% to 22% of the lesions biopsied. The task force members added that small diameter might not be indicative of early melanoma and invasiveness.

“They also reviewed alternate mnemonics for subtypes of melanoma, including ABCDEF for subungual melanoma, and additional ABCD criteria for pediatric melanoma. Other detection tools for early melanoma, including the Glasgow seven-point checklist, were reviewed.

“ ‘Although the diagnostic accuracy of ABCDEs has been verified in clinical practice and are a useful tool when used by dermatologists, to our knowledge, no randomized clinical trial has been performed to demonstrate that using the ABCDE criteria improves the ability to perform early detection by the public,’ the task force concluded. ‘Further research will be important to determine if the ABCDE criteria should be altered or set aside in favor of a newer paradigm.’ ”

ABCDE Method Often Misses Melanomas in Children

A common rule of thumb for diagnosing melanomas is not reliable in children. A new study evaluated the ABCDE method—asymmetry, border irregularity, color variation, diameter greater than 6 mm, evolution—in 70 children up to age 19 years who had been diagnosed with melanoma or treated for suspected melanoma. The ABCDE criteria did not apply to about 45% of them. Rather, these ‘nonstandard’ melanomas were often new, bled, bumpy, varied in diameter, and were one color or lacked pigment altogether (amelanotic). Of the 10 children who died, 7 had melanomas that lacked pigment. To diagnose melanoma in children more accurately, the researchers call for using new ABCD criteria—amelanotic; bleeding; bump; color uniformity; de novo, any diameter—in conjunction with the conventional ABCDE criteria.