Moles can grow over hair follicles, which explains why they can grow hair. Such hair growth usually indicates that the mole is a congenital nevus, meaning a person was born with it.
Although not all moles grow hair, those that do are usually healthy. Often, such hair is different from other body hair, faster growing, darker and much longer. This may be because the hair grows from very deep in the skin and must be coarser to penetrate the skin. However, the hair may not sprout until later in life, even when moles are congenital. Tweezing the hair out of a mole ? which may have to be repeated every two or three weeks ? is not harmful.
Moles that sprout hair suddenly are usually normal. Further, hairy moles are no more likely to develop cancer than similar moles without hair. However, any change in a mole can be a warning sign for melanoma, a deadly skin cancer. Check moles regularly, taking note of new moles and changes in older ones ? colors, sizes, shapes, textures and locations. Report any mole whose appearance makes you uncomfortable to your doctor immediately. Moles can be safely removed and biopsied, if necessary, to check for precancerous cells.