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How does malignant melanoma develop from melanocytes?

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skin rash caused by Lyme disease — skin disease Visible alterations in the texture of the skin, such as rashes and hives, can be indicative of serious disease. For example, one of the first signs of Lyme disease is a circular rash in a bull's-eye pattern on the skin.

Malignant melanoma develops when DNA damage causes melanocytes—the specialized cells responsible for producing skin-darkening melanin—to grow and divide uncontrollably. Unlike other skin growths, melanoma is always malignant.12

The process is primarily driven by genetic mutations that disrupt a cell's ability to regulate its own growth. A major cause of this DNA damage is exposure to ultraviolet radiation from sunlight or tanning devices. Specifically, about 50 percent of melanomas are associated with spontaneous mutations in the BRAF gene. This gene normally produces a kinase enzyme that helps regulate cell signaling, differentiation, and apoptosis (programmed cell death).21

When BRAF is mutated, it produces a constantly active, unregulated enzyme that transmits signals for cell proliferation continuously, regardless of external instructions. This aberrant activity initiates the development of cancer cells. Other genetic factors, such as inherited mutations in the CDKN2A tumor suppressor gene or variations in the MC1R gene, can also increase susceptibility to the disease.2