What are the symptoms of melanoma?

Diana Meeks
Diana Meeks on behalf of Sigma Nursing
Family Practitioner

Symptoms of melanoma are growths on the skin. These growths usually appear as a change in a mole that you already have or as a new skin growth. Generally, they're found on skin that's exposed to the sun, but they can form anywhere on the skin, including under fingernails and even internally. Normal moles usually have smooth edges, are symmetrical, and have a uniform color, so if you notice a mole that doesn't fit those characteristics, you should see a doctor. Other symptoms of melanoma include itchiness, scaliness, or oozing. Since symptoms vary from person to person, it's important to see a doctor if you think you may have melanoma.

Melanomas are usually painless. The signs of a melanoma are detected by following the A, B, C, D, and E mnemonic, which helps to look for the following:

  • Asymmetry- If the mole is asymmetrical (meaning that one half has a different shape than the other half) then the mole is suspect.
  • Border- If it has an irregular border it needs to be evaluated.
  • Color- If it is more than one color or changing colors it is time to see the doctor.
  • Diameter- If the diameter is larger than the top of a pencil eraser it needs to be evaluated.
  • Evolving or expanding- If the mole is changing it is time to get it checked out by your doctor.

It is important to check your moles on a regular basis. If melanoma is detected early, the survival rate is 99 percent.

These and other symptoms may be caused by melanoma. Other conditions may cause the same symptoms. A doctor should be consulted if any of the following problems occur:

A mole that:

  • Changes in size, shape, or color
  • Has an irregular edge or borders
  • Is more than 1 color
  • Is asymmetrical (if the mole is divided in half, the 2 halves are different in size or shape)
  • Itches
  • Oozes, bleeds, or is ulcerated (a hole forms in the skin when the top layer of cells breaks down and the underlying tissue shows through)
  • Change in pigmented (colored) skin
  • Satellite moles (new moles that grow near an existing mole)

This answer is based on source material from the National Cancer Institute.

Dr. Jill K. Onesti, MD
Surgical Oncologist

Melanoma is often discovered by the symptom of an abnormal lesion on your skin. These lesions can be described according to the ABCD pneumonic:

  • A for asymmetry: Two sides of the lesion do not mirror each other.
  • B for borders: The lesion does not have smooth, rounded borders.
  • C for color: Darker lesions are more concerning.
  • D for diameter: Larger lesions are typically more concerning. (A good rule of thumb is to see if it is larger than the size of a pencil eraser.) 

No single finding automatically proves that a lesion is melanoma, however. Some melanomas may not meet these criteria. It is important to mention to your doctor any lesion that is changing in terms of getting darker, getting larger, itching or bleeding.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.