Melanoma is the most dangerous type of skin Cancer. The most important warning sign for melanoma is a new spot on the skin or a spot that’s changing in size, shape, or color. Another important sign is a spot that looks different from all of the other spots on your skin. The ABCDE rule is another guide to the usual signs of melanoma. Some melanomas do not fit the rules described above, so it’s important to tell your doctor about any changes or new spots on the skin, or growths that look different from the rest of your moles.