Moles, also known as nevi, are common, particularly in people with fair complexions. Most people end up with between 30 and 40 moles during their lifetime. These skin growths are usually black or brown and can occur nearly anywhere on the body.
Most moles appear by the time a person turns 30, although their appearance can change during pregnancy, through sun exposure or as a part of the aging process. There are a number of different types of moles and most are completely harmless. However, because some moles can become cancerous, it is a good idea to have moles monitored regularly to assess changes to their appearance and possible treatment options.
Causes of Moles
Skin cells called melanocytes are responsible for the development of moles. These cells, which produce melanin, are distributed evenly throughout the skin and give skin its color. When these cells begin to clump together, moles can develop. Nearly every adult has at least a few moles. The more moles you have, the higher your risk for skin cancer. There are also different types of moles, and some types are more apt to become cancerous than others.
Types of Moles
There are a number of different types of moles, including the following:
- Congenital Nevus. This type of mole is present at birth. These types of moles occur in approximately one percent of the population and may be very large or relatively small. Congenital moles have a greater likelihood of becoming cancerous, so these should be evaluated, closely monitored or surgically excised if possible.
- Acquired Mole. This is a mole that develops after birth and is also referred to as a common mole. Most adults will develop 30-40 common moles over a lifetime. This type of mole is less likely to become cancerous , but if a moles is irregular, changing or causing symptoms it should be evaluated. People with large number of common moles may be more likely to develop skin cancer, so regular monitoring is essential.
- Dysplastic Mole. Also known as an atypical mole. These moles may be labeled as such because they have an unusual shape, size or color. While the appearance of these moles may seem concerning, they are not commonly cancerous. However, these are often biopsied to be sure. After microscopic evaluation, dermatopathologist grade dysplastic nevi as mild, moderate and severely atypical. Whether additional removal is done depends on the severity observed. People with atypical nevi have a higher risk than the general population of developing melanoma, particularly if they have five or more atypical nevi. Also patients with multiple family members with dysplastic nevi have an significantly higher risk of developing melanoma.
- Spitz Nevus. This type of mole looks most like melanoma and often requires further testing by a dermatologist to determine whether it is cancerous. These dome shaped growths are usually pink, but they can also be black, brown or red. These moles are fairly rare.
Treatment Options for Moles
Treatment for moles will depend on the following factors
- Asymmetry moles that are not symmetrical are more likely to be cancerous
- Border irregular or jagged borders of a mole may be a cause for concern
- Color variation with more than one color or varying shades of color should be checked by a doctor
- Diameter larger moles that are enlarging or are larger than 6 mm have higher risk.
In addition to these factors, moles that are changing or causing symptoms should be evaluated. Treatment may also be recommended if a mole is in an area that causes discomfort or is a cosmetic concern.
Before removal, a small injection of local anesthetic is given to make the area numb. Moles may be removed with a shave technique, punch technique or excision. A shave biopsy or removal is performed when superficial removal of skin is sufficient. A punch biopsy is performed when full thickness view of the skin lesion is needed. Punch biopsy takes small round core of tissue. A stitch is often required. Sometimes moles are removed by by excision (cutting the mole away from the skin using small incisions). This requires layers of stitches to allow for more rapid healing and better cosmetic outcome.
All of these procedures may be used to remove moles for cosmetic reasons as well.