It often occurs on the face, scalp, and other sun-exposed areas of persons who have spent a lot of time outdoors. Basal cell cancers grow slowly and generally do not spread, but they can reach a large size and penetrate deeply if not treated. Squamous cell carcinoma appears as a nodule or red scaly growth. It is more serious than basal cell cancer, because it can metastasize, or spread. If left untreated, it can even cause death.
Malignant melanoma is a rare but very aggressive form of skin cancer.
Because it spreads easily to other parts of the body, it must be treated promptly. Melanoma resembles a mole but with differences in color, size, and shape. It may appear as a new growth or a change in or near an existing mole. Cancerous moles usually are mostly dark brown or black with irregular patches of color that may include blue, red, or white. They tend to be asymmetrical in shape and have jagged edges or borders that are not well defined.