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Diagnosing Melanoma

Melanoma diagnosis involves careful skin inspection and biopsy of a suspicious skin lesion, which most often is pigmented (tan, brown, black, or bluish in color) but sometimes may be “amelanotic” (flesh colored, pink or red in coloration).  

How is melanoma diagnosed?

Physical examination, including dermoscopic evaluation (use of a magnifying device to look closer at moles) and biopsy are used to determine if a suspicious area on the skin is melanoma. In addition to a complete medical history, including family history, questions are asked about the mark on the skin, such as when it was first noticed,  whether and how it has changed in size or appearance, and whether it has become symptomatic with bleeding, pain, or itching.

The lesion of concern, as well as the moles and skin on the rest of your body are examined. The size, shape, color, texture, and presence of bleeding or scaling are usually noted.  If the lesion is clinically suspicious for melanoma, a skin sample (biopsy) will be performed and examined under the microscope. The biopsy procedure chosen depends on the site and size of the affected area.

Skin examination

A dermatologist checks the skin for moles, birthmarks, or other pigmented lesion that look abnormal in color, size, shape, or texture. Suspicious pigmented lesion should be biopsied to allow for microscopic evaluation by a pathologist. They should never be frozen with liquid nitrogen or cauterized (destroyed with a hot instrument or an electrical current), as this will not allow for appropriate histopathologic examination).


A local procedure (punch biopsy, deep, “saucerization” shave biopsy or fusiform excision) is performed to remove as much of the suspicious mole or lesion as possible. A pathologist then looks at the tissue under a microscope to check for cancer cells. Because melanoma can be hard to diagnose, pathologic evaluation by a pathologist trained in the evaluation of skin specimens (including a dermatopathologist) is preferable.

See also: Stanford Dermatopathology

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