Diagnosing Melanoma

Diagnosing Melanoma

If you are being seen at Seattle Cancer Care Alliance, you have most likely already been diagnosed with cancer. Your referring doctor based his or her diagnosis on a number of initial screenings, examinations, and diagnostic tests. Your medical history will be thoroughly reviewed at your first appointment. You may be asked a series of questions about your past medical and surgical problems, family history, personal cancer experiences, sun exposure, lifestyle, medications, and other risk factors. Your doctor will ask about your symptoms, when the skin lesion first appeared, and if it has changed in size or appearance. Your doctor will perform a thorough physical examination that may include checking the skin lesion in question, any other suspicious moles or marks, and checking for any enlarged lymph nodes. You then may have a skin biopsy which involves cutting a tissue sample of the suspicious area and sending it to the lab where a pathologist—a specialist who identifies diseases by studying cells and tissues under a microscope—examines your sample. The size and location of the problem helps determine the type of cancer you may have. Biopsies may leave a scar, so discuss your concerns with your doctor beforehand.

Common types of skin biopsies include:

  • Shave biopsy. A sterile razor blade is used to “shave-off” the abnormal-looking growth. Usually done if the lesion does not look suspicious or is too large to remove entirely.  
  • Punch biopsy. A special instrument called a punch is used to remove a circle of tissue from the abnormal-looking growth.
  • Excisional biopsy. A knife is used to remove the entire growth.
  • Wide local excision. This is a surgical procedure to remove some of the normal tissue surrounding the area where melanoma was found, in order to check for cancer cells.

Lymph node mapping and sentinel lymph node biopsy. This is a procedure in which a radioactive substance and a blue dye are injected near the tumor, usually at the time of wide local excision. The substance flows through lymph ducts to the draining sentinal node or nodes (the first lymph node or nodes where cancer cells are likely to spread). The surgeon removes only the nodes where the substance appears. A pathologist then checks the sentinel lymph nodes for cancer cells. Further surgery to remove more nodes may be recommended. Other tests that may be recommended, especially if your tumor is deep or have nodes involved, may include one or more scans of the following:

Computerized axial tomography (CAT) scan. Also called a CT scan, this procedure takes a series of detailed pictures of areas inside your body from different angles. A computer linked to an X-ray machine makes the pictures. An iodine-based dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. Pictures may be taken of the brain, chest, abdomen, and pelvis to see if the melanoma has spread. 

Chest X-ray. A chest X-ray is an X-ray of the organs and bones inside the chest. An X-ray is a type of energy beam that can go through your body and onto film, making a picture of certain areas inside your body. 

Position emission tomography (PET) scan. A PET scan uses glucose (a form of sugar) containing a radioactive atom. A small amount is injected into your arm. While lying in a PET machine, a special camera detects the radioactivity in any part of your body. Cancer cells generally absorb large amounts of the radioactive sugar and look brighter, so the doctor reading the PET scan can identify them. 

Magnetic resonance imaging (MRI). MRI scans use radio waves and strong magnets instead of X-rays. Energy from the radio waves is absorbed by your body and then released in a pattern formed by the type of tissue and by certain diseases, such as melanoma. A computer translates this pattern into a very detailed image of designated parts of your body. MRI of the brain may be ordered to rule out the spread of cancer to the brain.  Sometimes, MRI of other organs may be ordered as well in patients who may be allergic to iodine or the contrast used in the CAT scans. 

Bone scan. A bone scan looks for abnormalities in your bones. A small amount of a radioactive substance is injected into your blood stream. Aside from the injection, the procedure is painless. The scan uses a gamma camera that picks up radioactivity where it collects in your bones, identifying “hot spots” which can indicate bone cancer or other conditions like arthritis. 
Laboratory tests. Your doctor may order some medical procedures to test samples of your tissue, blood, urine, or other substances in your body. These tests help diagnose diseases, plan and monitor your treatment, and follow your disease over time.

The next step

Once your tests are completed, your team will determine your cancers stage (whether or not it has spread, and where it has spread). At this point treatment options will be discussed with you by your SCCA team of specialists.
Ask someone you trust to go with you to doctors' appointments and tests. This person can provide emotional support, help by asking questions and taking notes at visits, and help you research your disease and treatment options. Keep all your information, ideas, and questions organized, perhaps in a notebook.