Learn your ABCD's
Definitive diagnosis is made by biopsy
Melanomas are screened by the abcd's: a-asymmetry; b-irregular borders; c-different colors; d-diameber >6mm (size of pencil eraser). If you notice a mole with these characteristics, get it checked out asap. If you have a skin lesion which is growing, ulcerating, bleeding, or otherwise changing, get it seen as well for evaluation and possible biopsy.