Diagnosing Melanoma - Montefiore Medical Center

Tests that examine the skin are used to detect (find) and diagnose melanoma.If a mole or pigmented area of the skin changes or looks abnormal, the following tests and procedures can help detect and diagnose melanoma:

  • Skin examination: A doctor checks the skin for moles, birthmarks, or other pigmented areas that look abnormal in color, size, shape, or texture.
  • Biopsy: if your doctor is concerned about a particular mole, he or she will perform a biopsy, in which all or part of the growth is removed usually under local anesthetic. A pathologist then looks at the tissue under a microscope to check for cancer cells. Suspicious areas of the skin should be biopsied and not be shaved off or cauterized (destroyed with a hot instrument, an electrical current, or a caustic substance).

Determining the stage

After melanoma has been diagnosed, tests are done to find out if cancer cells have spread within the skin or to other parts of the body. Once there is a diagnosis of melanoma, the physician needs to determine what stage the melanoma is. The process used to find out whether cancer has spread within the skin or to other parts of the body is called staging. Staging will help your physician know if the melanoma has stayed in one area of the body (it is "localized"), or if it has spread ("metastasized") to other parts of the body. The stage of the melanoma plays a key role in decision about what treatment will be best. Early treatment is important. If melanoma is treated in its early stages, the chanced of recovery are very good. Left untreated, melanoma can spread throughout the body and become life threatening. The following tests and procedures may be used in the staging process:

  • wide local excision: a surgical procedure to remove some of the normal tissue surrounding the area where melanoma was found, to check for cancer cells;
  • lymph node mapping and sentinel lymph node biopsy: procedures in which a radioactive substance and/or blue dye is injected near the tumor; the substance or dye flows through lymph ducts to the sentinel node or nodes - the first lymph node or nodes where cancer cells are likely to have spread; the surgeon removes only the nodes with the radioactive substance or dye; a pathologist then checks the sentinel lymph nodes for cancer cells; If no cancer cells are detected, it may not be necessary to remove additional nodes;
  • chest x-ray;
  • CT scan;
  • MRI;
  • PET scan;
  • laboratory tests.