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Moles and Other Lesions

Moles are pigmented spots on the skin formed from clusters of melanocytes.  Moles may be acquired or congenital.


  • Acquired nevi appear during childhood or adulthood
  • Congenital nevi are present at birth


Some skin lesions may resemble melanoma but are in actuality noncancerous growths. When you see new growths, or old ones start to change, it's time to look at them more closely. By becoming familiar with your own skin lesions, you will be better able to tell those that are normal growths and those that need to be seen by your doctor. 

About Moles 

  • Definition: The medical term for a mole is melanocytic nevus. The term "nevus" is a medical term that means a collection of the same kind of cell. A melanocytic nevus, as the name suggests, means a collection of melanocytes. Because melanocytic nevi are by far the most common nevi seen or examined, doctors will often drop the word "melanocytic" and just refer to them as "nevus". The word "nevus" is the Latin word for "birthmark".
  • Shape: Moles may be flat or raised, round or oval, and are smaller than 6 millimeters, or 1/4 inch, in diameter, like the width of a pencil eraser. The borders are usually smooth and have a defined outline.
  • Color: Moles can be pink flesh tones to dark brown or black. Ordinary moles are usually a uniform brown, tan, or flesh-colored spot.

  • Number of moles: This is determined by one's genes and is based on the amount of sun exposure.

Changes in Moles 

  • The first sign of melanoma is sometimes a change in the size, shape, or color of an existing mole or the appearance of a new mole.

  • Usually, moles don't change in size, shape, and color from year to year.
  • Even though most people think that melanomas arise from pre-existing moles, many melanomas arise in "normal" skin, where there was no previous mole.  

  • If you notice changes in a mole or a new mole, contact your doctor for a medical evaluation.
  • Moles may emerge anywhere on the skin, either singly or in groups. Several moles may appear on the skin at the same time, especially in areas that have been exposed to the sun. Moles may darken following sun exposure or during pregnancy.

  • During adulthood, they often lose their pigmentation, and they may even seem to disappear in old age. Most moles will follow a pattern of aging over the course of an individual's life. As moles "age" they commonly will slowly "raise up" so they can be felt, and over years to decades very slowly lose their color. They eventually become very soft and turn the same color as the rest of the skin. For this reason, some elderly appear to have no moles, when in fact their moles have gone through this normal life cycle called "senescence", and are not noticeable unless one looks carefully. 
  • Remember, these normal changes occur VERY slowly, while changes in moles that make one concerned about possible melanoma occur quickly; in the order of weeks to months. 
  • If you ever have a question about a change in a mole, do not brush it off. Always see a physician who can look at it with you.


For more information on moles click here.



Consult a doctor immediately if you notice a change in any of your moles or a new mole.


  • Most skin lesions are harmless and normal and remain the same throughout our lives.

  • Moles are also called melanocytic nevi. They are the result of an increased number of pigment cells (melanocytes) in close proximity to one another.

  • Once a mole has developed, its size, shape, and color tend to change little from year to year.

  • Melanoma can arise from a pre-existing mole or a new mole that develops in adulthood.