Skin cancer occurs when abnormal skin cells begin to grow out of
control. While normal cells divide and develop in an orderly
fashion, cancer cells do not. Skin cancer cells may penetrate or
invade surrounding tissue. They may also spread to other parts
of the body through the blood or lymphatic systems. As cancer
cells continue to grow, they crowd out normal cells and often
form into a mass of tissue called a growth or tumor. These
growths may inhibit normal body function by blocking up internal
organs or blood vessels, or destroying nerve pathways, etc. Skin
cancer (mostly melanoma) can sometimes lead to death.