Melanoma Skin Cancer

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Early Detection, Diagnosis, and Staging TOPICS

Signs and symptoms of melanoma skin cancer

Unusual sores, lumps, blemishes, markings, or changes in the way an area of the skin looks or feels may be a sign of melanoma or another type of skin cancer, or a warning that it might occur.

Normal moles

A normal mole is usually an evenly colored brown, tan, or black spot on the skin. It can be either flat or raised. It can be round or oval. Moles are generally less than 6 millimeters (about ¼ inch) across (about the width of a pencil eraser). A mole can be present at birth, or it can appear during childhood or young adulthood. New moles that appear later in life should be checked by a doctor.

Once a mole has developed, it will usually stay the same size, shape, and color for many years. Some moles may eventually fade away.

Most people have moles, and almost all moles are harmless. But it is important to recognize changes in a mole – such as in its size, shape, or color – that can suggest a melanoma may be developing.

Possible signs and symptoms of melanoma

The most important warning sign for melanoma is a new spot on the skin or a spot that is changing in size, shape, or color. Another important sign is a spot that looks different from all of the other spots on your skin (known as the ugly duckling sign). If you have any of these warning signs, have your skin checked by a doctor.

The ABCDE rule is another guide to the usual signs of melanoma. Be on the lookout and tell your doctor about spots that have any of the following features:

  • A is for Asymmetry: One half of a mole or birthmark does not match the other.
  • B is for Border: The edges are irregular, ragged, notched, or blurred.
  • C is for Color: The color is not the same all over and may include shades of brown or black, or sometimes with patches of pink, red, white, or blue.
  • D is for Diameter: The spot is larger than 6 millimeters across (about ¼ inch – the size of a pencil eraser), although melanomas can sometimes be smaller than this.
  • E is for Evolving: The mole is changing in size, shape, or color.

Some melanomas do not fit the rules described above. It is important to tell your doctor about any changes or new spots on the skin, or growths that look different from the rest of your moles.

Other warning signs are:

  • A sore that does not heal
  • Spread of pigment from the border of a spot to surrounding skin
  • Redness or a new swelling beyond the border
  • Change in sensation – itchiness, tenderness, or pain
  • Change in the surface of a mole – scaliness, oozing, bleeding, or the appearance of a bump or nodule

Be sure to show your doctor any areas that concern you and ask your doctor to look at areas that may be hard for you to see. It is sometimes hard to tell the difference between melanoma and an ordinary mole, even for doctors, so it’s important to show your doctor any mole that you are unsure of.


Last Medical Review: 10/29/2013
Last Revised: 10/29/2013