A malignant melanoma is a skin cancer that spreads to other areas of the body, primarily the lymph nodes, liver, lungs, and central nervous system.
Most melanomas begin in a mole or other pre-existing skin lesion.
Excessive exposure to sun is a major factor in causing malignant melanoma. It usually affects the skin of the head, neck, legs, or back, but rarely occurs in the eye, mouth, vagina, or anus. Melanomas are more likely to occur in adults, but some affect children. The incidence of melanomas has increased since 1970. Hospitalization for radiation treatment and chemotherapy, if the child's tumor has spread.