Moles, also called nevi (singular: nevus), can be found on almost everyone's body, anywhere there is skin. Most are harmless and do not need to be treated except for aesthetic reasons. However, the signs of melanoma, a type of skin cancer, can often be mistaken for a mole, while melanoma can form inside or around a mole. Thus, it is important to get acquainted with your moles and know how they work. If you believe you have skin cancer or have been diagnosed, learn about potential treatment options.

Moles are classified as congenital (formed at birth) and acquired (form during a person's life). Examine your skin routinely and detect any new or abnormal moles to prevent precancerous skin lesions.

What Does a Normal Mole Look Like?

Moles come in a wide variety of colors, but a normal mole should be a single color throughout. They are also roughly circular in shape, with smooth rather than irregular borders, and should be flat or slightly raised. Their appearance may change over time, growing or shrinking or changing colors, but they do so slowly.

Some moles, known as Spitz moles, can be raised enough to form a dome shape. They may have mottled colors and bleed or ooze fluid. While they can be mistaken for melanoma, a dermatologist can tell the difference.

Atypical Moles

Moles that do not fit the pattern described above are called atypical or dysplastic moles. These include moles that are larger than the eraser end of a pencil, have unusual shapes and irregular borders, and/or have multiple colors.

Atypical moles are not necessarily cancerous, but should be examined by a dermatologist to rule out cancer.

Moles and Melanoma

Moles can demonstrate a risk factor for melanoma. The following are all warning signs:

  • Very large congenital moles
  • A large number of moles, more than 50
  • Frequent acquired moles
  • More than four atypical moles
  • Moles that change color, size, and/or shape quickly

Mole Treatment

Moles normally do not need to be treated unless they are uncomfortable, the dermatologist thinks they might be cancerous, or the patient wants them removed for aesthetic reasons.

Mole removal is a simple procedure that can be done under local anesthesia in the dermatologist's office. It normally takes only one visit, but may require two. For larger moles, the dermatologist will use a scalpel to cut it out and stitch up the incision. A smaller mole can simply be shaved off with a sharp blade. A patient should never try to remove a mole at home -- doing so can lead to scarring, infection, and if the mole is cancerous, it could possibly spread cancer cells through the body.