Melanoma, also called malignant melanoma, is a type of skin cancer. It's often caused by too much sun exposure. The first sign of melanoma is often a new mole or a change in the appearance of an existing mole. Melanoma can usually be treated with surgery if it's found early. If it has spread, you may need other treatments, such as radiotherapy. Exposure to light from the sun is thought to cause most melanomas, but there's evidence to suggest that some may result from sunbed exposure. You cannot