What are moles?

A mole, or naevus, is a normal skin growth that develops when pigment-producing cells (melanocytes) grow in groups. They appear as small, dark marks, or sometimes flesh-coloured small bumps, on your skin. 1

Different types of moles

Benign nevi

Benign nevi are normal moles. They are not a sign of melanoma, or skin cancer. Benign nevi have a very low chance of turning into skin cancer.

Dysplastic nevi

Dysplastic nevi are also called atypical nevi. Dysplastic nevi may have edges that are not perfectly round. They can have more than one color. They can also be flat or raised. Dysplastic nevi have a low chance of turning into skin cancer. 

Congenital nevi

 Congenital nevi are moles that your child was born with or developed soon after birth. If your child has many congenital nevi or a large congenital nevus, he has a slightly higher risk of developing skin cancer later in life. 2

When to see a doctor

The following ABCDEs are important signs of moles that could be skin cancer. If a mole displays any of the signs listed below, have it checked immediately by a dermatologist:

  • Asymmetry: One half of the mole does not match the other half
  • Border: The border or edges of the mole are ragged, blurred, or irregular
  • Color: The mole has different colors or it has shades of tan, brown, black, blue, white, or red
  • Diameter: The diameter of the mole is larger than the eraser of a pencil
  • Evolving: The mole appears different from others and/or changing in size, color, shape 3