When to See Your Doctor

Skin cancer is most treatable and curable when discovered early.

Melanoma skin cancer can appear anywhere on the body. It may be a mole that changes in color, size, or flakes or bleeds. Or, it can simply be a large dark brownish spot or a shiny, firm bump on your body.

Non-melanoma skin cancer lesions may be an open sore that does not heal, a firm red nodule, or other skin changes. Because skin cancer can take so many forms, it's important to report any sores, moles, bumps, or flat areas that strike you as odd. Perform monthly self-examinations of your skin so you can find changes.

Look at pigmented lesions (moles) for these ABCDs:

Asymmetry -- one half unlike the other

Border irregular -- scalloped or poorly circumscribed border

Color varied from one area to another; shades of tan and brown; black; sometimes white, red or blue

Diameter larger than 6mm as a rule (diameter of a pencil eraser)

Examine for these other types of lesions:

• Basal cell carcinoma. Can occur anywhere on the skin, but the most dangerous lesions tend to form on the face, on or near the nose or corners of the eyes.

  Look for these features:

  • Single red, pearly (shiny) bump
  • Single plaque (flat area) with clearly defined margin
  • Tendency to bleed, scab up and heal
  • Sunken middle portion that may look like a scar or ulcer (red, like an open wound)

Squamous cell carcinoma. Usually occurs on sun-exposed skin from a precancerous lesion, chronic sore or scar.

Look for these features:

• Usually a single red, yellowish or brown lesion
• Thick, scaly, "wart-like" irregular surface
• Tends to become raised and firm

More on Skin Cancer

In the Encyclopedia:

This article was reviewed and updated June 2007.