I noticed a new dark mole with uneven edges this month, and my dermatologist can’t see me until after the holidays. What could this be?

Moles, or nevi, are usually benign skin growths that develop from melanocytes, the pigment-producing cells in the skin. While most moles are harmless, a new mole or changes in an existing mole can sometimes indicate skin cancer. Dark moles with uneven edges can be of particular concern, as these are characteristics associated with atypical moles or melanoma.

Melanoma is less common than other types of skin cancer but is more likely to spread if not caught early. The irregularity of the edges and a darker color might suggest that the mole is atypical. It is important to be vigilant, especially if the mole is larger than 6 millimeters in diameter, roughly the size of a pencil eraser.

Atypical moles, also known as dysplastic nevi, differ from common moles in several ways. They may be larger than normal moles, have indistinct or irregular borders, and display a mix of colors ranging from tan to dark brown. These moles can appear anywhere on the body, though they are commonly found on the trunk.