Stages of melanoma diagnosis

Staging melanoma is the process used to describe the extent of the disease. The doctor will take into account the tumor thickness and depth and whether the melanoma cells have spread, or metastasized, to the lymph nodes or other parts of the body. Staging helps the melanoma treatment team develop an appropriate treatment plan and determine the prognosis (outlook).

Melanoma Stage
Description
Treatment Option
0 The tumor is confined to epidermis and has not entered the dermis, a deeper layer of the skin. This stage of melanoma is also called melanoma in situ. The tumor and some surrounding tissue are removed surgically. Usually no further treatment is necessary; however, continued skin examination to evaluate for a new melanoma or other skin cancer will continue.
IA The tumor is less than 1 millimeter thick. The outer layer of skin does not look cracker or scraped (ulcerated). It has not spread to any lymph nodes or other organs. The tumor and some surrounding tissue are removed surgically. Usually no further treatment is necessary.   
IB The tumor is either less than 1 millimeter thick and ulcerated, or 1–2 millimeters thick and not ulcerated. It has not spread to any lymph nodes or other organs.  The tumor and some surrounding tissue are removed surgically. Usually no further treatment is necessary. 
IIA The tumor is either 1–2 millimeters thick and ulcerated, or 2–4 millimeters thick and not ulcerated. It has not spread to any lymph nodes or other organs.  The tumor and some surrounding tissue are removed surgically. Usually no further treatment is necessary. 
IIB The tumor is either 2–4 millimeters thick and ulcerated, or more than 4 millimeters thick and not ulcerated. It has not spread to any lymph nodes or other organs.  The tumor and some surrounding tissue are removed surgically. Additional treatment(s) may be recommended. 
IIC The tumor is more than 4 millimeters thick and is ulcerated. These are aggressive tumors that are more likely to spread.  The tumor and some surrounding tissue are removed surgically. Additional treatment(s) may be recommended. 

IIIA

IIIB

IIIC

The tumor may be of any thickness. It may or may not be ulcerated. The cancer cells have spread either to a few nearby lymph nodes, or to some tissue just outside the tumor but not to the lymph nodes. The tumor and lymph nodes that have cancer cells are removed surgically. Additional treatment(s) may be recommended. 
IV The cancer cells have spread to the lymph nodes, other organs in the body, or areas far from the original site of the tumor. This is called metastatic melanoma. The tumor and lymph nodes that have cancer cells are removed surgically. Additional treatment(s), like immunotherapytargeted therapy or clinical trials may be recommended.
 

Additional Melanoma Staging Information

The American Joint Committee on Cancer (AJCC) staging system is used to stage melanoma. The AJCC uses the TNM system to determine the melanoma stage. The overall stage is a combination of the T, N and M. This information should also be included on your pathology report

T for primary tumor

The T category is based on primary tumor thickness. 

  • Tx: Tumor cannot be evaluated.
  • T0: No evidence of cancer.
  • Tis: Melanoma in situ describes a cancer that is confined to the outer layer of the skin.
  • T1: Primary tumor depth is < 1.0mm
    • T1a: no ulceration and mitotic rate < 1/mm2
    • T1b: with ulceration or mitotic rate > 1/mm2
  • T2: Primary tumor depth is between 1.01 and 2.0mm
    • T2a: no ulceration
    • T2b: with ulceration
  • T3: Primary tumor depth is 2.01 to 4.0mm
    • T3a: no ulceration
    • T3b: with ulceration
  • T4: Primary tumor depth is > 4.0mm
    • T4a: no ulceration
    • T4b: with ulceration

N for regional lymph nodes

The N category is based on lymph nodes containing or not containing cancer cells.

  • Nx: Lymph nodes cannot be evaluated
  • N0: No evidence of cancer in the lymph nodes
  • N1: There are melanoma cells in 1 lymph node, further described by:
    • N1a: micrometastasis (can be seen by microscope, but not felt by physical exam)
    • N1b: macrometastases (can be felt by physical exam)
  • N2: There are melanoma cells in 2 or 3 lymph nodes, further described by:
    • N2a: micrometastasis (can be seen by microscope, but not felt by physical exam)
    • N2b: macrometastases (can be felt by physical exam)
    • N2c: in transit or satellite lesions but NO positive lymph nodes
  • N3: Any of the following:
    • > 4 lymph nodes with melanoma cells
    • 2-3 positive lymph nodes that appear stuck together or "matted"
    • In transit or satellite lesions with any number of positive lymph nodes

M for distant metastasis

The M category is used to describe melanoma metastasis throughout the body. 

  • Mx: metastases cannot be evaluated
  • M0: No evidence of metastases
  • M1a: the melanoma has spread from the primary site to other areas of the skin or under the skin, or distant lymph nodes
  • M1B: Melanoma has spread to the lungs
  • M1c:
    • Melanoma has spread to any other organ with a normal LDH level (Lactate dehydrogenase)
    • Melanoma has spread to any site and LDH is elevated