Signs & Symptoms

Change in an existing mole is the most common symptom of melanoma. Education regarding the warning signs of early melanoma has been achieved through the use of the American Cancer Society's ABCD system of detection, which includes looking for changes in the following attributes of a mole:


One half of the mole or skin growth doesn't match the other half.

Border irregularity

The edges of the mole or skin growth are ragged, notched, or blurred.


The pigmentation of the growth is not uniform. Shades of tan, brown, and black are present. Dashes of red, white, and blue may create a mottled appearance. A part of the mole may lose its color. Changes in color distribution, especially the spread of color from the edge of a mole into the surrounding skin may occur.


The mole or skin growth is larger than 6 mm (0.2 in.), or about the size of a pencil eraser. Size may increase rapidly; however, any growth of a mole should be of concern.

Other signs of melanoma in a mole include changes in:

  • Elevation:
    A previously flat mole may thicken or rise up.
  • Surface:
    The mole may become scaly, erode, ooze, bleed, become crusted or ulcerate.
  • Surrounding skin:
    Skin around the mole may become red or swollen, or develop small new patches of color around a larger lesion (satellite pigmentations).
  • Sensation:
    The mole may begin to itch, burn, or become painful.
  • Consistency:
    The mole may soften and small pieces of skin may break off easily (friability).

Photographs are sometimes used to document and detect changes in the skin, especially atypical moles. Computers may be utilized to compare photographs of suspicious moles and lesions taken from exam to exam to more accurately determine whether a mole or lesion is changing.