Genetic Markers
The moles that are found on the skin throughout the body can often be referred to as a nevus. A nevus can range from small to large and is typically round in shape. If can be found in several different colors such as brown, black red or pink. One of the ways that skin moles form is from a pre-genetic marker that everyone is born with. The genetic marker is the foundation from which all moles grow, form and change throughout our lifetime. People who have close family members would have had in cancer such as basal cell carcinoma or melanoma have a very high risk of developing skin cancer themselves based on their genetic markers. Genetic markers also determine how many moles someone may have and how large they may become regardless of skin damage or sun exposure.
Aging
Another reason a skin mole forms or changes its shape is due to the aging process. As we age our skin changes. New growths may begin to develop or existing skin moles may start to grow or change in their appearance. The skin moles that were once part of the surface of the skin rather than on top of it, may begin to rise and change color. Not only is this caused from aging it can also be caused from hormonal changes and shifts in a human body. As some people age, the melanocytes in the skin may begin to spread, cluster or darken. Melanocytes are skin cells that contain pigment to give skin its color. Typically when moles begin to spread or appear as age spots they can easily be confused with congenital nevi and dysplastic nevi. Many people are born with both congenital and dysplastic nevi but dysplastic nevi tend to change as people age and can develop into melanoma---a serious and deadly form of skin cancer.
Sun Exposure
Sun exposure can also cause skin moles to form and existing moles to change in size and shape. Sun exposure that occurred from a very young age without protection from UV rays is one way to get skin damage and develop the new growth of moles. When the UV rays penetrate the skin, melanocytes begin to produce melanin. Melanin is generally dispersed evenly on the surface of the skin but sometimes clusters to one location. A change in the skin cells can result in a lesion or skin mole. Many of these moles are pre-cancerous in nature and are referred to as actinic keratosis. Skin moles that are newly formed or those that begin to change shape or size should be evaluated for skin cancer. There are three main types of skin cancer: basal cell carcinoma, squamous cell carcinoma and melanoma. Basal cell carcinoma is a serious skin cancer. It forms deep within the epidermis and can be life threatening if not treated early. Basal cells can be difficult to see because they can develop under the skin before a mole or skin change is noticeable. Squamous cell occurs mainly on the epidermis, rarely spreads and is treatable in its early stages. Squamous cells appear as rough and flaky raised skin moles but can be hard to detect. Melanomas are dark and irregular in shape and appearance. They are the deadliest of all skin cancers and can spread very rapidly to other vital organs causing death if left untreated.
