Melanomas May Appear Noticeably Different Than Other Moles

 

A preliminary study suggests that melanomas have a different appearance than other irregular skin moles (i.e., are “ugly ducklings”), according to a report in the January issue of Archives of Dermatology, one of the JAMA/Archives journals.

Alon Scope, M.D., of the Memorial Sloan-Kettering Cancer Center, New York, and colleagues obtained images of the backs of 12 patients from a database of standardized patient images. All of the patients had at least eight atypical moles, and five patients had one lesion that had been confirmed as a melanoma. Thirty-four study participants—including eight pigmented lesion experts, 13 general dermatologists, five dermatology nurses and eight non-clinical medical staff—were asked to evaluate the images and identify lesions that looked different from all other atypical moles.

All five melanomas and only three of 140 benign lesions (2.1 percent) were generally apparent as different, meaning that two-thirds of the participants identified them as “ugly ducklings.” “The malignant melanomas were apparent as being different to at least 85 percent of participants, whereas the agreement rate on the benign lesions perceived as being different was 76 percent at most,” the authors write. “Four lesions were generally apparent as completely different, all four bei asked to evaluate the images and identify lesions that looked different from all other atypical moles.

All five melanomas and only three of 140 benign lesions (2.1 percent) were generally apparent as different, meaning that two-thirds of the participants identified them as “ugly ducklings.” “The malignant melanomas were apparent as being different to at least 85 percent of participants, whereas the agreement rate on the benign lesions perceived as being different was 76 percent at most,” the authors write. “Four lesions were generally apparent as completely different, all four being malignant melanomas.”

For all participants, the test had a sensitivity of 90 percent, meaning 90 percent of the melanomas were identified as different. Sensitivity was 100 percent for the pigmented lesion experts, 89 percent for general dermatologists, 88 percent for nurses and 85 percent for non-clinicians.

“Although the sensitivity and specificity and diagnostic accuracy of the ugly duckling sign depended on clinical expertise, the values for these parameters were good in all subgroups of participants,” the authors write. “These preliminary findings suggest that the ugly duckling sign may prove to be a useful screening strategy for primary health care providers and even for skin self-examination.”

Arch Dermatol. 2008; 144[1]:58-64.