Medical Dermatology

Atypical Moles

Atypical moles are generally larger than normal moles, variable in color, and have irregular borders compared to regular moles. Atypical moles occur most often on the back and also occur commonly on the chest, abdomen and legs in women, but they may occur anywhere on the skin surface. Multiple atypical moles on the skin represent an increased risk for melanoma in that individual. When examining moles, consider the following “ABCD” features:

  • Asymmetry – One half of the mole does not match the other half.
  • Border irregularity –ragged, notched or blurred borders instead of smooth round borders.
  • Color – The pigmentation/color of the mole is not uniform.
  • Diameter – moles larger than a pencil eraser (6mm) are more likely to be atypical.

Moles that meet some or all of these criteria should be checked by a dermatologist.