Malignant Melanoma Staging 

Updated: Apr 10, 2018
  • Author: Winston W Tan, MD, FACP; Chief Editor: Dirk M Elston, MD  more...
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TNM Classification for Malignant Melanoma

The American Joint Committee on Cancer (AJCC) tumor/node/metastasis (TNM) classification and staging system for cancer are provided below. [1, 2]  

Table 1. TNM Classification for Malignant Melanoma (Open Table in a new window)

Primary tumor (T)

TX

Primary tumor cannot be assessed (ie, curettaged melanoma)

T0

No evidence of primary tumor

Tis

Melanoma in situ

T1

Thickness ≤1.0 mm 

T1a: <0.8 mm without ulceration 

T1b: <0.8 mm with ulceration, or 0.8-1.0 mm with or without ulceration

T2

 Thickness >1.0-2.0 mm

T2a: Without ulceration

T2b: With ulceration

T3

Thickness >2.0-4.0 mm

T3a: Without ulceration

T3b: With ulceration

T4

Thickness >4.0 mm 

T4a: Without ulceration

T4b: With ulceration

Regional lymph nodes (N)

NX

Regional nodes cannot be assessed (ie, previously removed for another reason)

N0

No regional metastases detected

N1

One tumor-involved lymph node or in-transit, satellite, and/or microsatellite meastases with no tumor-involved nodes

N1a: One clinically occult (ie, detected by sentinel lymph node biopsy [SLNB]; no in-transit, satellite, or microsatellite metastases

N1b: One clinically detected; no in-transit, satellite, or microsatellite metastases

N1c: No regional lymph node disease; in-transit, satellite, and/or microsatellite metastases found

N2

Two or three tumor-involved nodes; or in-transit, satellite, or microsatellite metastases

N2a: Two or three clinically occult (ie, detected by SLNB); no in-transit, satellite, or microsatellite metastases

N2b: Two or three clinically detected; no in-transit, satellite, or microsatellite metastases

N2c: One clinically occult or clinically detected; in-transit, satellite, and/or microsatellite metastases found

N3

≥4 tumor-inolved nodes or  in-transit, satellite, and/or microsatellite metastases with ≥2 tumor-involved nodes or any number of matted nodes without or with in-transit, satellite, and/or microsatellite metastases 

N3a: ≥4 clinically occult (ie, detected by SLNB); no in-transit, satellite, or microsatellite metastases

N3b: ≥4, at least one of which was clinicallly detected, or presence of any matted nodes; no in-transit, satellite, or microsatellite metastases

N3c: ≥2 clinically occulr or clinically detected and/or presence of any matted nodes, with presence of in-transit, satellite, and/or microsatellite metastases

Distant metastasis (M)

M0

No detectable evidence of distant metastases

M1a

Metastases to skin, soft tissue (including muscle), and/or nonregional lymph nodes

M1b

Lung metastasis, with or without M1a involvement

M1c

Distant metastasis to non–central nervous system (CNS) visceral sites with or without M1a or M1b involvement

M1d

Distant metastasis to CNS, with or without M1a or M1b involvement

Cases of metastasis (beyond M0) in which the lactate dehydrogenase (LDH) level is known are given the suffix (0), for normal LDH level, or (1), for elevated LDH level

 

Anatomic stage/prognostic groups

Table 2. Clinical staging (Open Table in a new window)

Stage

T

N

M

0

Tis

N0

M0

IA

T1a

N0

M0

IB

T1b

N0

M0

T2a

N0

M0

IIA

T2b

N0

M0

T3a

N0

M0

IIB

T3b

N0

M0

T4a

N0

M0

IIC

T4b

N0

M0

III

Any T, Tis

N1, N2, or N3

M0

IV

Any T

Any N

M1

Table 3. Pathologic staging (Open Table in a new window)

Stage

T

N

M

0

Tis

N0

M0

IA

T1a, T1b

N0

M0

IB

T2a

N0

M0

IIA

T2b, T3a

N0

M0

IIB

T3b, T4a

N0

M0

IIC

T4b

N0

M0

IIIA

T1a/b, T2a

N1a, N2a

M0

IIIB

T0

N1b, N1c

M0

T1a/b, T2a

N1b/c, N2b

M0

T2b, T3a

N1a/b/c, N2a/b

M0

IIIC

T0

N2b/c, N3b/c

M0

T1a/b, T2a/b, T3a

N2c, N3a/b/c

M0

T3b, T4a

Any N ≥N1

M0

T4b

N1a/b/c, N2a/b/c

M0

IIID

T4b

N3a/b/c

M0

IV

Any T, Tis

Any N

M1

Stage IA:

  • Lesions ≤1 mm in thickness with no evidence of ulceration or metastases (T1aN0M0) are associated with a 5-y survival rate of ~97%

Stage IB:

  • Lesions ≤1 mm in thickness with ulceration noted but without lymph node involvement (T1bN0M0) or lesions 1.01-2 mm in thickness without ulceration or lymph node involvement (T2aN0M0) are associated with a 5-y survival rate of ~92%

Stage IIA:

  • Melanomas >1 mm but ≤2 mm in thickness with no evidence of metastases but with evidence of ulceration (T2bN0M0) or lesions 2.01-4.0 mm in thickness without ulceration or lymph node involvement (T3aN0M0) are associated with an overall 5-y survival rate of ~81%

Stage IIB:

  • Melanomas 2.01-4 mm in thickness with ulceration but no lymph node involvement (T3bN0M0) or lesions >4 mm in thickness without ulceration or lymph node involvement (T4aN0M0) are associated with a 5-y survival rate of ~70%

Stage IIC:

  • Lesions >4 mm in thickness with ulceration but no lymph node involvement (T4bN0M0) are associated with a 5-y survival rate of ~53%

Stage IIIA:

  • Patients with any-depth lesion, no ulceration, and 1 positive (micrometastatic) lymph node (T1-4aN1aM0) have a 5-y survival rate of ~70%

  • T1-4aN2aM0 lesions (any-depth lesion, no ulceration, but 2-3 nodes positive for micrometastasis) are associated with a 5-y survival rate of 63%

Stage IIIB:

  • Patients with any-depth lesion, positive ulceration, and 1 lymph node positive for micrometastasis (T1-4bN1aM0) or 2-3 nodes positive for micrometastasis (T1-4bN2aM0) have a 5-y survival rate of 50-53%

  • Patients with any-depth lesion, no ulceration, and 1 lymph node positive for macrometastasis (T1-4a, N1b, M0) or 2-3 nodes positive for macrometastasis (T1-4aN2bM0) have a 5-y survival rate of 46-59%

Stage IIIC:

  • Patients with any-depth lesion, positive ulceration, and 1 lymph node positive for macrometastasis (T1-4bN1bM0); 2-3 nodes positive for macrometastasis (T1-4bN2bM0); or ≥4 metastatic lymph nodes, matted lymph nodes, or in-transit met(s)/satellite(s) have a 5-y survival rate of ~40%

Stage IV:

  • Melanoma metastatic to skin, subcutaneous tissue, or lymph nodes with normal LDH level (M1a) is associated with a 5-y survival rate of ~15%-20%

  • M1b disease (metastatic disease to lungs with normal LDH level) has a 5-y survival rate of 7%

  • M1c disease (metastatic disease to all other visceral organs and normal LDH level or any distant disease with elevated LDH level) is associated with a 5-y survival rate of 10%

Mitotic rate assessment

For mitotic rate assessment, the pathologist counts the number of cells in a certain amount of melanoma tissue that are in the process of dividing. A higher mitotic rate means that the cancer is more likely to grow and spread. The mitotic rate is used to stage thin melanoma.