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The American Joint Committee on Cancer has developed a system for classifying cancers according to the extent of the cancer. This system is also used in Canada.

Complete excision of the melanoma is followed by assessment of lymph nodes and other parts of the body to determine whether the cancer has spread. The staging system looks at other factors that have been found to affect survival, such as tumour thickness (Breslow level), depth of invasion (Clark level), and ulceration.1

Two systems are used for staging melanoma.

  • The clinical staging system uses information gained from the removal of the melanoma and from blood tests and X-rays for any spread of the cancer.
  • The pathologic staging system uses information gained from the removal of the melanoma and from pathological examination after lymph nodes are removed (lymphadenectomy).

The clinical staging system uses the letter T to describe primary tumours, the letter N to describe lymph node involvement, and the letter M for metastases (spread). Numbers after each of these letters show the seriousness of the disease.

Clinical staging system for melanoma
Category Description

Tumour (describes the primary tumour)

  • TX: Primary tumour cannot be assessed.
  • T0: No evidence of primary tumour
  • Tis: Melanoma that invades only the outer layer of skin (melanoma in situ)
  • T1: Melanomas 1.0 mm or less in thickness, with possible ulceration
  • T2: Melanomas 1.01–2.0 mm, with possible ulceration
  • T3: Melanomas 2.01–4.0 mm, with possible ulceration
  • T4: Melanomas more than 4.0 mm, with possible ulceration

Nodes (describes whether cancer has spread into the lymph nodes)

  • NX: Lymph nodes cannot be examined.
  • N0: No metastasis found in lymph nodes.
  • N1: Metastases based on number of metastatic nodes and is present in one lymph node.
  • N2: Metastasis present in 2 or 3 lymph nodes.
  • N3: Metastasis is present in four or more lymph nodes.

Metastasis (describes the extent of cancer spread outside primary melanoma site)

  • M0: No evidence of melanoma cells elsewhere in the body
  • M1a: Metastases to skin, subcutaneous, or distant lymph nodes
  • M1b: Metastases to lung
  • M1c: Metastases to all other visceral sites or distant metastases to any site combined with an elevated serum LDH

The pathologic staging system uses all the above information and adds the pathologic evaluation of the lymph nodes and the examination of any evidence of melanoma spread.

Pathologic staging system for melanoma
Pathologic stage Description

Stage 0

Tis, N0, M0

Stage 1A

T1a, N0, M0

Stage 1B

T1b, N0, M0

T2a, N0, M0

Stage IIA

T2b, N0, M0

T3a, N0, M0

Stage IIB

T3b, N0, M0

T4a, N0, M0

Stage IIC

T4b, N0, M0

Stage IIIA

T1–4a, N1a, M0

T1–4a, N2a, M0

Stage IIIB

T1–4b, N1a, M0

T1–4b, N2a, M0

T1–4a, N1b, M0

T1–4a, N2b, M0

T1–4a, N2c, M0

Stage IIIC

T1–4b, N1b, M0

T1–4b, N2b, M0

T1–4b, N2c, M0

Any T, N3, M0

Stage IV

Any T, Any N, M1

Related Information



  1. American Joint Committee on Cancer (2010). Melanoma of the skin. In AJCC Cancer Staging Manual, 7th ed., pp. 325–344. New York: Springer.


By Healthwise Staff
Primary Medical Reviewer Kathleen Romito, MD - Family Medicine
Primary Medical Reviewer Anne C. Poinier, MD - Internal Medicine
Specialist Medical Reviewer Alexander H. Murray, MD, FRCPC - Dermatology
Last Revised March 14, 2011

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