Melanoma

The ABCDE rule

• A — Asymmetry. One half doesn't match the other.
• B — Border that is irregular, notched or poorly defined.
• C — Color that varies within the same lesion.
• D — Diameter larger than 6 mm.
• E — Evolving: it changed, it bleeds, it itches, it doesn't heal.

E is the one that matters most. An ugly mole that has looked the same for twenty years is less concerning than an ordinary one that changed in six months.

Where nobody thinks to look

A share of melanomas appear in places people never check:

• The soles of the feet and between the toes.
• Under a nail: a dark line that widens, or that stains the skin at the edge of the nail.
• The scalp.
• Areas with little sun exposure, including mucous membranes.

How it is diagnosed

Clinical examination with a dermatoscope, which sees the structure below the surface, and photographic follow-up when something needs watching. If there is suspicion, a biopsy under local anesthesia.

The diagnosis comes from the tissue, not from the eye. That is why it cannot be ruled out from a photograph.

Who should be checked every year

• Family history of melanoma.
• Many moles, or large moles present since birth.
• Fair skin that burns and doesn't tan.
• Severe sunburns in childhood.
• Personal history of skin cancer.