Melanoma is a kind of skin cancer that starts when skin cells called melanocytes grow out of control. Cancer cells can spread to other parts of the body and grow there. When cancer cells do this, it’s called metastasis. To doctors, the cancer cells in the new place look just like the ones that started in the skin.
https://www.cancer.org/cancer/melanoma-skin-cancer/if-you-have-melanoma.html

