WEDNESDAY, Jan. 23 Melanoma may look noticeably different -- like "ugly ducklings", actually -- compared to other irregular skin moles that are benign, say researchers at the Memorial Sloan-Kettering Cancer Center in New York City.

Rates of melanoma are increasing and early identification enables surgeons to treat the disease by removing the tumor, according to background info in the study.

Melanoma is more frequent among people with many moles or other skin marks, particularly if they're uncommon in color, shape or size. It can be a challenge for doctors to distinguish between melanoma and similar-looking moles that are benign.

In this study, the researchers had 34 people -- eight pigmented lesion experts, 13 common dermatologists, five dermatology nurses and eight non-clinical medical staff -- check photos of the backs of 12 people. They all had at least eight uncommon moles, and five of them had one melanoma lesion.

The study participants were asked to evaluate the photos and identify lesions that looked different from all other uncommon moles. All five melanomas and only 3 -- of 140 -- benign lesions (2.1 percent) were identified as being different.

"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 study authors wrote. "Four lesions were usually apparent as utterly different, all four being malignant melanomas."

The pigmented lesion experts identified 100 percent of the melanomas, compared with 89 percent for common dermatologists, 88 percent for nurses, and 85 percent for non-clinicians.

"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," the researchers concluded.

The study was published in the January issue of the Archives of Dermatology.

More information

The American Academy of Family Physicians has more about melanoma.