Dermatoscope image of malignant melanoma in situ with microinvasion of superficial spreading melanoma (SSM) type in a 43 year old patient who grew up in South Africa. Melanoma is a form of skin cancer that arises from melanocytes, the cells that produce melanin, the pigment that gives skin its colour. This is a melanoma in situ, an early form of the cancer confined to the outer most layer of cells in the skin. The main cause of melanoma is exposure to ultraviolet radiation in sunlight. It is an aggressive cancer that often spreads to other parts of the body. If this occurs, the prognosis is poor. Treatment is with surgical excision of the melanoma. For an image of the malignant melanoma eight months later, please see C056/6744.