Moles
Moles are growths on the skin that are usually brown or black. They can appear anywhere on the skin, alone or in groups. Most moles appear in early childhood and during the first 20 years of a person's life, however, some moles might not appear until much later in life. It is normal to have between 10 to 40 moles by adulthood. As the years pass, moles usually change slowly, becoming raised and lighter in color. Often, hairs develop on the mole. Some moles will not change at all, while others will slowly disappear over time.
What Causes Moles?
Moles occur when cells in the skin grow in a cluster instead of being spread throughout the skin. These cells are called melanocytes, and they make the pigment that gives skin its natural color. Moles might darken after exposure to the sun, during the teen years, and during pregnancy.
Treatments
If a dermatologist believes the mole needs to be evaluated further or removed entirely, he or she will first take a biopsy (small tissue sample of the mole) to examine thin sections of the tissue under a microscope. This is a simple procedure. (If the dermatologist thinks the mole might be cancerous, cutting through the mole will not cause the cancer to spread.)
If the mole is found to be cancerous, the dermatologist will cut out the entire mole along with a rim of normal skin around it, and then stitch the wound closed.