In order to diagnose melanoma, providers may use a combination of tests, such as a standard physical exam, a technique called dermoscopy that utilizes a lighted magnifying instrument, careful examination of the lymph nodes, and one or more biopsy procedures, such as a skin biopsy or lymph node biopsy.

When melanoma is suspected, the initial biopsy will be conducted with a narrow margin to preserve as much healthy tissue as possible. In the event that the biopsy is positive for melanoma, the site will usually be re-excised with an appropriate margin, determined by the depth of the lesion.

Blood tests and imaging tests such as x-rays, CT scans or MRI scans may be used in some cases, as well. Early diagnosis of melanoma is important, so that treatment can begin as soon as possible. Even though it is the most deadly form of skin cancer, when limited to the outermost layers of skin, melanoma treatment usually produces a 95 percent cure rate.