Melanoma Diagnosis

Imaging & biopsy

In determining whether a mole contains any malignant cells, doctors take a biopsy — removing all or part of the abnormal area — and send to a pathologist for examination and testing. For suspected melanomas, your physician will likely do one of these procedures:

  • Shave biopsy – a thin, sharp blade shaves off the abnormal tissue
  • Excisional biopsy – The physician uses a scalpel to remove the entire mole or growth and some tissue around it. You will have local anesthesia so you won’t feel pain.

If the area of concern is very large or difficult to remove completely, you may have:

  • Incisional biopsy – only a piece of the lesion or mole is removed
  • Punch biopsy – a sharp, hollow device removes a small but deep sample of tissue


Melanoma staging refers to how deep in the skin the cancer has grown and whether, and to where, it has spread. Your melanoma will be described as one of these stages:

Stage 0: The cancer involves only the top layer of skin. This stage is also called “melanoma in situ.”

Stage I: The tumor no more than 1 mm thick (about the width of sharpened pencil point). The mole’s surface may have broken down. Or the melanoma may be larger, 1 to 2 mm, but the surface is not broken down.

Stage II: The melanoma is 1 to 2 mm thick or larger and the surface has broken down.

Stage III: Melanoma cells have spread to at least one nearby lymph node or other nearby tissues.

Stage IV: Cancer cells have spread to the lung or other organs, skin areas or far away lymph nodes. Melanomas may spread to the liver, brain, bones and other organs.

Other diagnostic tests

Because melanoma is more likely to spread than other skin cancers, you may have additional blood tests and imaging to learn whether the cancer has grown deeper in the skin, spread to lymph nodes, or other parts of the body such as the lungs. Whether or not cancer is found in these areas helps determine the stage of your cancer.

These additional tests may include:

  • Blood tests
  • Chest x-ray
  • Computerized tomography (CT)
  • Magnetic resonance imaging (MRI)
  • Positron Emission tomography (PET)
  • Lymph node tests
    • Sentinel lymph node biopsy – removing cells, a portion of the node or the entire lymph node most likely (such as closest in proximity) to contain cancer
    • Fine needle aspiration – uses a thin needle to remove cells from a lymph node
    • Excisional lymph node biopsy – removes a portion of a lymph node

Melanoma Treatment