Use this A-B-C-D-E checklist to help identify unusual moles that might indicate melanoma that need to be examined by a physician:
— A is for asymmetrical. Look for moles with irregular shapes, such as two very different-looking halves.
— B is for irregular border. Look for moles with irregular, notched or scalloped borders — characteristics of melanomas.
— C is for changes in colour. Look for growths that have many colours or an uneven distribution of colour.
— D is for diameter. Look for new growth in a mole larger than about six millimetres.
— E is for evolving. Look for changes over time, such as a mole that grows in size or that changes colour or shape.
Moles may also evolve to develop new signs and symptoms, such as new itchiness or bleeding. Other suspicious changes may include: scaliness; itching; spreading of pigment from the mole into the surrounding skin; oozing or bleeding.
Cancerous moles vary greatly in appearance. Some may show all of the above changes, while others may have only one or two unusual characteristics.
Source: Mayo Clinic