Melanoma is the most dangerous form of skin cancer because it can spread in the body.
Melanoma starts in the outer layer of the skin, and can develop in weeks or months, or take years. It can appear as a new mole or freckle-like spot on the skin, or develop in an existing mole. They are usually dark in colour.
Melanoma can appear anywhere on the skin, but it most common on the back, leg, arm, scalp, or face.
Melanoma is most often caused by excessive ultraviolet (UV) exposure from the sun or tanning beds.
The biggest risk factors for melanoma are:
Fair, sun sensitive skin that burns rather than tans
Red or blond hair
Many moles - more than 50
Moles which are large or unusual in colour or shape
A close family history of melanoma, or a personal history of melanoma
Excessive UV exposure from the sun or sun beds
A history of severe sunburns
Melanomas are clearly visible on the outer surface of the skin. Perform regular skin checks on yourself, and let your doctor know if you have any unusual symptoms.
The ABCDEs of Malignant Melanoma
Asymmetry - the shape on one side is different than the other side
Border - the border or visible edge is irregular, ragged, or imprecise
Colour - there is a colour variation with brown, black, red, grey, or white within the lesion
Diameter - growth is typical of melanoma
Evolution - look for change in colour, size, shape, or symptoms, such as itchiness, tenderness, or bleeding.
For more information, click the links below for information on melanoma from the Canadian Dermatology Association and the Canadian Cancer Society.