Harmless mole or scary melanoma? At Frontiers in Optics 2010, an annual meeting of international optic scientists in Rochester, New York, October 24-28, experts will present a new technique that may help doctors better distinguish between the two.

To visually inspect the surface of a patient's skin, doctors can now use a handheld lens, bright light or microscopes, and a technique called dermoscopy. But recent studies have found that diagnoses based on these images are often problematic, because only the skin's surface is visible, and the dangerous changes lurking beneath can't be detected.

"There's quite a bit of variability in the diagnoses provided this way," said Thomas Matthews, researcher at Duke University in North Carolina in a news release October 20. The best way to diagnose melanoma, he said, is still a biopsy, the removal and analysis of a tissue from the suspicious mole. But even then, doctors often disagree on the diagnosis. False positives drive up healthcare costs and inflict unnecessary treatments on patients; false negatives can be fatal.

Matthews and his colleagues at Duke's Center for Molecular and Biomolecular Imaging are adapting a laboratory imaging technique to provide new information about suspicious moles, both on live tissue and from biospies.

Skin contains two kinds of pigments, or melanins, and studies suggest that changes in the ratio of these two pigments may signal when a harmless mole has become malignant. Matthews' "two-photon microscopy technique pumps a very small amount of energy" into the pigments, similar to a laser, "then watches the energy redistribute to give high-resolution images of their distributions in a spot of skin," states the release.

"No one has been able to look at where different melanins are organized in skin," said Matthews. "This opens up a whole new pathway of looking for melanoma." With further research, the scientists hope this technology could be used to avoid biopsies altogether.

For more on Frontiers in Optics 2010: http://www.osa.org/

To see a melanoma slideshow and learn about risks and treatment: http://www.medicinenet.com/melanoma/article.htm