ABCDEs of melanoma skin cancer

Photos of various melanoma, showing one with asymmetry, one with border irregularity, one with varied colour, and one larger than 1/2 centimetre, and three images showing evolution of size of melanoma.

Source: NCI Visuals Online. Skin Cancer Foundation. www.cancer.gov.

The ABCDEs of melanoma skin cancer are:

  • Asymmetry. One half doesn't match the appearance of the other half.
  • Border irregularity. The edges are ragged, notched, or blurred.
  • Colour. The colour (pigmentation) is not uniform. Shades of tan, brown, and black are present. Dashes of red, white, and blue add to a mottled appearance.
  • Diameter. The size of the mole is greater than 6 mm (1/4 inch), about the size of a pencil eraser. Any growth of a mole should be evaluated.
  • Evolution. There is a change in the size, shape, symptoms (such as itching or tenderness), surface (especially bleeding), or colour of a mole.

Current as of: March 1, 2023

Author: Healthwise Staff
Medical Review:
Kathleen Romito MD - Family Medicine
Amy McMichael MD - Dermatology
Donald Sproule MDCM, CCFP - Family Medicine