Skin moles are growths that form from clusters of pigment cells called melanocytes. They commonly appear during childhood or adolescence, and may also be present at birth or arise in later life. Most people have multiple skin moles. However, in some cases, the presence of multiple moles or moles of a certain type may indicate an increased risk for the development of skin cancer.
The Basics
The average person has between 10 and 40 skin moles, although some people have hundreds, according to the American Academy of Dermatology, or AAD. Depending on individual circumstances, your moles may appear as tiny dots or grow to an inch or more in diameter. They may also show a range of variations in color, height and texture. If you have light skin, you will generally have a larger number of moles than darker-skinned individuals. Moles typically do not hurt or itch, and once they appear they remain permanently on your skin, the Merck Manuals Online Medical Library notes. Although they are not a form of cancer, cancerous changes sometimes occur in or near mole tissue.
Common Moles
Common moles that form in childhood or adolescence typically have certain characteristics, including regular borders, symmetrical halves, consistent size and consistent coloration at any given point in time, the AAD notes. If you have an average number of these moles, you typically have no increased risks for skin cancer, the AAD reports. However, if you have more than 50 to 100 common moles, your risks of developing cancer rise in comparison to the rest of the population.
Dysplastic Moles
In some cases, you may develop moles that don’t have the symmetry, smooth borders, constant size and consistent color associated with common moles, the AAD explains. These atypical moles, which appear in roughly 10 percent of the population, are called dysplastic nevi, according to the Merck Manuals. They tend to run in families, and if you have even a few of them, you have an increased risk for skin cancer development. Tell your doctor if you have moles with dysplastic characteristics, especially if they grow or change over time.
Congenital Moles
Roughly 1 percent of people have moles at birth, the AAD reports. You may have one or more of these congenital moles, in sizes that range from small dots to large areas with diameters in excess of 8 inches. Although smaller congenital moles are typically harmless, the presence of large moles poses an increased cancer risk.
Considerations
To safeguard your health, you should monitor all moles for potentially dangerous changes. The AAD notes that you can develop moles almost anywhere, including between your toes and fingers, on your scalp, under your nails and on your palms or the soles of your feet. To properly gauge the number of moles on your body and monitor your cancer risks, you will need to check these areas in addition to more plainly visible locations. See your doctor for further advice on multiple moles.
