The primary cause of metastatic melanoma is ultraviolet radiation from the sun, states WebMD. It can occur even on parts of the body not exposed to the sunlight such as the retinas and palms of hands.
Melanoma is a skin cancer that can spread to other regions of the body, causing adverse health effects or death, explains MedicineNet. It may spread to areas such as tissues under the skin, the lungs, the liver and the brain, says WebMD.
In healthy skin, new cells form, replacing the older cells, notes Mayo Clinic. Sometimes, melanocytes, which are cells that produce pigments that give the skin its color, may not function properly, developing DNA damage. This action causes an uncontrollable multiplication of cells, which eventually become cancerous. As of 2015, the cause of DNA damage is unknown, but doctors believe that exposure to ultraviolet radiation from the sun or tanning lamps is the primary cause.
Risk factors for metastatic melanoma include light hair, a family history of melanoma, Caucasian ancestry and light-colored eyes, states MadicineNet. If melanoma spreads to other areas of the body, patientd may experience bone pain, loss of appetite, trouble breathing and hardened lumps under the skin, as WebMD details.