Doctors diagnose melanoma using methods that include skin biopsy, fine needle aspiration biopsy, and surgical lymph node biopsy, according to the American Cancer Society. Blood tests may also be useful in diagnosing melanoma.
When diagnosing melanoma, the first step is usually a medical history evaluation. The doctor may ask when the change on the skin first appeared and if there has been a change in size and appearance since first noticed, says the American Cancer Society. The doctor may ask the patient about possible risk factors for skin cancer, such as sunburns and tanning, and if anyone in the patient's family has had skin cancer.
During the physical exam, the doctor takes note of the shape, color, size and texture of the area and asks the patient if the area has been crusting, oozing or bleeding. The doctor may examine the entire body of the patient for other spots that may be related to skin cancer, says the American Cancer Society.
The doctor may also examine the patient's lymph nodes to check for any abnormalities. Enlarged lymph nodes may suggest the melanoma has spread there. If the primary doctor suspects melanoma, he may refer the patient to a dermatologist for more testing, states the American Cancer Society.