It’s time to learn whether that mole you’ve wondered about is more serious than a simple blemish. The medical center’s dermatology department is offering free skin cancer screening Saturday from 9 a.m. to noon at the Stanford Health Library in the Stanford Shopping Center.

Melanoma, the most deadly form of skin cancer, starts as an irregularly shaped blemish the size of a pencil eraser. It may be shades of tan and black, red, white or blue and may bleed or itch. Anyone can get melanoma, but it is more common in light-skinned people, said Susan Swetter, MD, assistant professor of dermatology.

People who were exposed to a lot of sun as a child or teenager are at higher risk, as are those who have many moles, have a close relative with melanoma or have been diagnosed with melanoma in the past. Swetter urged people with those risk factors to come to the screening.

Most skin cancers, Swetter said, could be prevented by staying out of the sun, using sunscreen and wearing clothing that doesn’t let sunlight hit your skin.

"The biggest problems we run into are insufficient application of sunscreen, failure to reapply after swimming or sweating, and the lack of sun-protective clothing," she said.

Call the Stanford Health Library at 725-8400 for details.