Melanoma is a form of skin cancer that usually stands out because of its irregular brown or dark colour. This form of cancer arises from the pigment cells (melanocytes) of the skin. It can be a completely new spot or arise from a pre-existing mole. Common symptoms include; change in colour, shape, growth, itching or spontaneous bleeding. Sometimes the melanoma causes little or no symptoms. A mole that looks different from other birthmarks (a so-called 'ugly duckling' among the other birthmarks) may possibly be a melanoma.