Slow-growing melanomas lose structure over time

New York - Results of a new study suggest the diameter of most slow-growing melanomas changes very little over time, but that the lesions can become more disorganized, less structured and change or develop new colors.

Researchers led by Vitaly Terushkin, M.D., of Memorial Sloan-Kettering Cancer Center, retrospectively assessed a dermoscopic-image dataset of 92 slow-growing melanomas from 15 pigmented lesion clinics that were sequentially followed for one year or more, HealthDay News reports. Changes in global pattern, organization, color, structure and size were evaluated at baseline and follow-up.

On follow-up the researchers found that:

The dermoscopic pattern of the melanomas became more homogeneous and less reticular;

The melanomas had more frequent disorganization of pattern;

There was a reduction in the prominence of dermoscopic structure of pigmented network and a simultaneous increase in the prominence of areas with no structure;

They developed more melanoma-specific dermoscopic structures;

Color changes included a decrease in light brown and increases in the prominence of dark brown and the frequency of new colors, such as red, white, gray, blue and black.

The researchers found that 75 percent of lesions grew by less than 2 mm or remained the same size; an increase in size correlated to the total number of colors and structures.

“Physicians should pay particular attention to melanocytic lesions that, over time, become more disorganized, reveal a loss of network in favor of structureless areas, develop a negative network, and exhibit new colors such as dark brown, black, gray, blue red, and white,” the authors wrote. “In addition, one should not rely solely on change in size.”

The study appears in the June issue of the British Journal of Dermatology.

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