The first step in diagnosing skin melanoma is usually a biopsy. A tissue sample is taken during a biopsy and sent to a pathologist (a doctor who specializes in diagnosing disease). The pathologist examines the cells under a microscope and will determine the type of melanoma and the stage. There are also several noninvasive techniques that can help doctors make a diagnosis. For example, in dermoscopy, doctors use a handheld device to magnify a suspicious area of skin. Doctors can also use highly advanced imaging technologies that can map melanoma in precise detail. Learn more about melanoma diagnosis.