When a biopsy shows the presence of melanoma, the next step is to determine the cancer's stage, how large the tumor is and how far it has spread. These findings will form the basis for decisions about how to treat the disease most effectively.

The official guidelines for staging melanoma were updated in 2009 by the American Joint Committee on Cancer (AJCC), a distinguished group of experts from national healthcare organizations and major cancer centers around the country. Member organizations include the American Cancer Society, the American College of Surgeons, the American Society of Clinical Oncology, and the Centers for Disease Control and Prevention.

Melanoma Center's Staging Tool will guide you through the process of identifying the stage of your melanoma.

Factors of Prognosis

The revised melanoma staging system is based on the risk factors most important in determining prognosis. They include:

  • Tumor thickness (also known as Breslow thickness ): how deeply the tumor has penetrated the skin. Thickness is measured in millimeters (mm). Thinner tumors carry a more favorable prognosis than thicker tumors. The thicker the tumor, the greater the risk of tumor metastasis.

  • The presence or absence of tumor ulceration.
    Ulceration is a condition in which the epidermis that covers a portion of the primary melanoma is not intact. Ulceration is determined by microscopic evaluation of the tissue by a pathologist, not by what can be seen with the naked eye. Ulcerated tumors pose a greater risk for metastatic disease than tumors that are not ulcerated.

  • The number of metastatic lymph nodes.
    The greater the number of lymph nodes containing melanoma, the less favorable the prognosis.

  • Mitoses within the primary tumor.
    Mitoses are active cell division of the tumor and can be defined in terms of number. This will be determined by the pathologist who diagnoses the melanoma and should be reported for each primary melanoma within the pathology report. The more mitoses, the more aggressive the tumor seems to be growing.

  • Whether metastasis to the lymph nodes is microscopic or macroscopic.
    Micrometastases are tiny tumors not visible to the naked eye. They can be detected only by microscopic evaluation after sentinel lymph node biopsy or elective lymph node dissection. Macrometastases can be felt during physical examination or seen by the naked eye when inspected by a surgeon or pathologist. Their presence is confirmed by lymph node dissection or when the tumor is seen to extend beyond the lymph node capsule. Macrometastases carry a less favorable prognosis than micrometastases.

  • The site of distant metastasis.
    Distant metastases to the skin, the subcutaneous tissue, or distant lymph nodes carry a relatively better prognosis than distant metastases to any other site in the body.

  • Level of serum lactate dehydrogenase (LDH).
    LDH is an enzyme found in the blood and many body tissues. Elevated LDH levels usually indicate the presence of metastatic disease and a less favorable prognosis than normal LDH levels.