Your family doctor can first examine your skin for signs of melanoma. Then, if melanoma is suspected, s/he may refer you to a dermatologist, who will look at the area more closely.
Usually the first step for any diagnosis of melanoma is a medical history. The doctor y will ask you about your age, when the mark on the skin first appeared, and whether it has changed in size or appearance. You may also be asked about past exposures to known causes of skin cancer and whether anyone in your family has been diagnosed with skin cancer, or not.
After a full medical history, your doctor will then request a physical exam. During the physical exam, your doctor will note the size, shape, color, and texture of the skin area(s) in question, and whether bleeding or scaling is present. The rest of your body will also be checked for spots and moles that may be related to skin cancer. The doctor may also palpate the lymph nodes to check for symptoms that cancer has spread.
If an abnormal area of skin raises the possibility of skin cancer, certain medical exams and tests may be used to confirm whether the problem is caused by melanoma, non-melanoma skin cancer, or some other skin condition. If melanoma is found, other tests may be done to determine if it has spread to other areas of the body. A skin sample will probably be examined during a biopsy.
Biopsy - If the doctor thinks a melanoma might be present, s/he will take a sample of skin for exam under a microscope. The choice of skin biopsy method depends on the size of the affected area and its location on your body. Skin biopsies are performed using a local anesthetic injected into specific area. Special tests can then be performed on a biopsy samples to identify the kind of cancer. This is important because different cancers are often given different treatments. These types of biopsies may be more involved than those used to sample the skin.
Excisional or incisional biopsy - This type of biopsy is often used when a wider or deeper portion of the skin is needed or to remove an enlarged lymph node, a tumor, or a portion of a tumor.
Fine needle aspiration (FNA) biopsy - This type of biopsy involves a thin needle to remove very small pieces from a tumor. A fine needle aspiration (FNA) biopsy is not used to diagnose a suspicious mole, but it may be used to biopsy large lymph nodes near a melanoma
Punch biopsy - Punch biopsies involve taking a deeper sample of skin with a biopsy instrument that removes a short cylinder, or "apple core," of tissue.
Sentinel lymph node mapping and biopsy - This has become a common procedure to determine if melanoma has spread to the lymph nodes. This procedure identifies lymph nodes that drain lymph fluid from the area of the skin where the melanoma started.
Shave biopsy - This type of biopsy involves removing the top layers of skin by shaving then off.
Bone scan - A bone scan is used to search for spread of cancer to the bones, but it is rarely used in melanoma. This test is only performed when other test results or symptoms suggest that cancer may have spread to the bones.
Imaging tests - Imaging tests create pictures of the inside of the body and are used to identify the possible spread of melanoma to lymph nodes or other organs in the body. They are not needed to diagnose people in early stages of melanoma, when melanoma is unlikely to have spread.
Chest x-ray - this x-ray helps determine whether melanoma has spread to the lungs, or not.
Computed tomography (CT) - The CT scan is a type of x-ray test that produces detailed, cross-sectional images of the body and can show the detail in soft tissues. Ct scans are used to confirm if any lymph nodes or organs are enlarged, which can be caused by the spread of melanoma or to determine whether melanoma has spread to the lungs, or not.
Magnetic resonance imaging (MRI) - An MRI scan uses radio waves and strong magnets instead of x-rays to create a very detailed image of parts of the body.
Positron emission tomography (PET) - PET scans are used to see if cancer has spread to lymph nodes. During a PET scan, a doctor injects glucose that contains a radioactive atom into the blood. Because cancer cells in the body grow quickly, they absorb large amounts of the radioactive sugar. A special camera can then create a picture of areas of radioactivity in the body for analysis.
Microscopic exams - Microscopic exams investigate lymph nodes under the microscope for signs of melanoma. This is also the procedure user for "sentinel lymph nodes" that are non-palpable, but may still contain cancerous cells.
When melanoma is found and diagnosed, more tests are performed to identify if cancer cells have spread to other parts of the body. This process is called "staging", and is necessary before cancer treatment can begin. Learn the difference between Stage 0 - 1 - 2 and Stage 3 melanoma here.