Signs and Symptoms

Often, the first sign of melanoma is a change in the size, shape, color or feel of an existing mole. Most melanomas have a black or blue-black area. Melanoma also may appear as a new, black, abnormal or "ugly-looking" mole.

Rarely, melanoma is not pigmented and is more difficult to diagnose. It may appear as a non-healing ulcer or a new scar-like lump in the skin.

The warning signs are sometimes referred to as ABCDE:

  • Asymmetry — Two halves of a lesion that are not the same
  • Border — Borders of a lesion are irregular, scalloped or vague
  • Color — Color varies from one area to another, including shades of tan or brown as well as black, blue, red and white
  • Diameter — A lesion that is greater than 6 millimeters in diameter, about the size of a pencil eraser
  • Evolution — Lesions that change or evolve

The "ABCDE" rule is an easy guide to the usual signs of melanoma.

Some melanomas don't fit the ABCDE rule, so it's important to be aware of changes in skin markings or new spots.

Other warning signs are:

  • A sore that doesn't heal
  • A new growth
  • Spread of pigment, or color, from the border of a spot to surrounding skin
  • Redness or a new swelling beyond the border of a mole
  • Change in sensation such as itchiness, tenderness or pain
  • Change in a mole's surface such as scaling, oozing, bleeding or the appearance of a bump or nodule

Contact your primary care doctor or dermatologist if you find changes that match the ABCDE signs or these other warning signs.

Reviewed by health care specialists at UCSF Medical Center.