What You Should Know about Moles

Published in Dermatology, Wellness Tag: Julie Schultz, MD  

Author: Julie Schultz, MD

As a dermatologist, I receive a lot of questions about moles. It's important to know what a normal mole looks like and what to do if you think you have an abnormal mole.

Moles and the Different Types of Moles

Moles are a tumor in a skin—a neoplasm, which is a spot in the skin full of melanocytes or the pigment cells in the skin. There are different colored moles. They can be skin-colored to light brown or dark brown to black. You may be born with moles, which are called congenital nevi or birthmarks. There are also moles you acquire throughout life. Most moles, including acquired moles, are benign, but others are may have a higher risk of turning into skin cancer.

Some People Are More Prone to Moles than Others

Genes play a role in whether or not you have moles. In fact, some people are more prone to moles because it runs in the family. Often children have very few moles when they are young, and babies typically don't have many moles. You tend to acquire more as you get older. New moles after the age of 25 are somewhat concerning. If you get a lot of new dark, changing moles they may be cancerous so be attentive to new moles and make an appointment with your provider if you think it may be cancer.

We aren't sure why people have moles. We think they may possibly signify a family relation, like stripes on a tiger, because often family members will have the same types of moles.

For some people the more sun exposure they get, the larger their moles grow or the more their moles may transform. Usually the concern of sun is that UV exposure can turn moles into cancer, which is why we encourage people to stay out of the sun. The only way to prevent moles from developing is to reduce sun exposure. We know the more people sit in the sun, the more moles they will get.

Normal Moles Verses Cancerous Moles

Normal moles tend to be smaller than a head of pencil eraser, less than six millimeters in diameter. They should have an even color and should be perfectly symmetrical. In other words, you should be able to fold it in half and it would be able to fold back perfectly on itself. They should be stable; they shouldn't be changing.

We follow the ABCDE to know if your mole could potentially be cancerous. If a mole fits the description of any of the following, there is a concern that it could be melanoma. Typically if a mole becomes cancerous, it will be melanoma although there are other kinds of skin cancer.

  • Asymmetry — Cut in half, it won't fold back perfectly on itself.
  • Border Irregularity — The border or edges of the mole are ragged, blurred or irregular.
  • Color or Changing Moles — The color of the mole is not the same throughout or has multiple shades of tan, brown, black, blue, white or red.
  • Diameter — The mole is larger than a head of a pencil eraser.
  • Evolving — The mole is changing in size, shape or color.

What are the other risk factors of moles?

Moles can be cancerous, but most moles are not. We do not recommend people removing all of their moles to prevent melanoma. It's never been shown to be an effective method. We encourage patients to look at their moles no more than once a month. When you look too often, you won't see any change. All of a person's moles should look like they go together with similar colors and sizes. I usually say they will all look alike. Be more concerned about the mole that sticks out like the ugly ducking. If your mole is abnormal, we typically surgically remove it.

It's very important if you are suspicious of a mole or you see it changing to get it checked out as soon as possible. When diagnosing and treating melanoma, if caught early, it is very treatable. But when caught late, it can be fatal.