Malignant melanoma is the least common of the three main skin cancers, but the most aggressive. While melanoma only accounts for about 4% of all skin cancers, it is responsible for more than 73% of skin cancer deaths. Melanoma is a form of skin cancer that arises from melanocytes – the cells that produce pigment which gives the skin its color and protects it from sun damage. People with darker skin produce more melanin and are therefore more protected. Melanocytes often cluster together and form moles (nevi). Most moles are benign, but some may go on to become malignant melanomas.
Melanomas are divided into 4 main types, depending on their location, shape and whether they grow outward or downward into the dermis:
Superficial Spreading Melanoma: This often begins as a flat dark stain on the skin or appears as a change to a pre-existing mole. It accounts for 2/3 of all melanomas.
Nodular Melanoma: This is usually unrelated to a pre-existing mole. A smooth nodule appears, and it is often blue-black in color – it may grow rapidly and spread to the lymph glands quickly.
Acral Lentiginous Melanomas: This occurs on the palms of the hand, on the soles of the feet or under nail beds, and can grow and spread quickly. In dark-skinned people it accounts for most of melanomas.
Lentigo Maligna Melanoma: This is quite common on chronically sun-exposed skin and usually appears on the face of elderly people. If you notice any changes to an existing mole, or new skin growths, have a dermatologist examine them. The chance of beating melanoma is greatest when the tumor is new, and can be removed in its entirety.