Melanoma is a rare and life-threatening skin disease. It starts in the melanocytes, which are the cells in your skin that create melanin. Melanin is the pigment that gives rise to skin color.
Melanoma may develop from moles in your skin. They can develop on the skin anywhere in your body, including the insides the mouth or vagina.
Metastatic melanoma happens when the malignant growth spreads from the tumor to different parts of your body. This is otherwise called stage 4 melanoma. Melanoma will end up metastatic if not treated early.