Moles (Nevi)

Formed from the cells that produce pigment called melanocytes, moles are non-cancerous skin growths. Moles are small in size, have a well-defined border and appear as a single shade of pigment, usually beige to dark brown. Most of the time moles develop in the first 20 years of life. Usually, the moles on the same individual look similar in size and color.

Causes
When skin cells grow in a cluster instead of separately, a mole is formed. Melanocytes, the cells that cause the moles, actually make the pigment that gives skin its natural color. Sun exposure, the teen years, and pregnancy can cause a mole to darken.

Types of Moles
There are four main types of moles:

• Congenital Nevi
  Occurring in about 1 in 100 people, congenital nevi are moles that appear at birth. Congenital nevi moles may have a greater tendency to develop into melanoma than moles that appear later in life.

• Dysplastic Nevi
  Larger than average and irregular in shape, dyplastic nevi tend to have uneven color with dark brown centers and lighter, uneven edges. These moles are hereditary. One person can develop more than 100 moles.

• Halo Nevi
  When the skin surrounding small moles becomes lighter and the central moles turn pale, these types are called halo nevi. Usually benign, halo nevi may increase the risk of vitiligo, a skin disorder.

• Blue Nevus
  A deep-seated blue mole that is very common in West Indian infants.

When to Be Concerned
Generally speaking, moles do not pose a significant health concern. Pay attention to any changes in a mole because they could indicate an occurrence of melanoma or skin cancer. Watch for:

• Color change, especially darkening
• Increase in size or an increasingly irregular appearance
• Itchiness or pain
• Spontaneously bleeding

Treatment
If a patient finds a particular mole bothersome, does not like the location or skin cancer is possible, a dermatologist might remove the mole through surgical excision, which involves cutting out the entire mole and stitching the skin closed. Another option involves using a surgical blade to shave away the mole. The dermatologist can usually perform the procedure in the office. If skin cancer is suspected, the doctor will biopsy the mole.

Prevention
One of the best ways to protect against skin cancer is to take caution in the sun. Reduce exposure to the sun by:

• Applying a water-resistant, broad-spectrum sunscreen
• Limiting time in the sun
• Looking for changes in your skin regularly
• Protecting children from the sun
• Wearing long pants and long-sleeved shirts
• Wearing a broad-brimmed hat