Table 5 Definition of distant metastasis (M)

From: Melanoma pathology reporting and staging

 

M criteria

M Category

Anatomic site

LDH level

M0

No evidence of distant metastasis

Not applicable

M1

Evidence of distant metastasis

See below

 M1a

Distant metastasis to skin, soft tissue including muscle, and/or nonregional lymph node

Not recorded or unspecified

  M1a(0)

Not elevated

  M1a(1)

Elevated

M1b

Distant metastasis to lung with or without M1a sites of disease

Not recorded or unspecified

 M1b(0)

Not elevated

 M1b(1)

Elevated

M1c

Distant metastasis to non-CNS visceral sites with or without M1a or M1b sites of disease

Not recorded or unspecified

 M1c(0)

 

Not elevated

 M1c(1)

 

Elevated

M1d

Distant metastasis to CNS with or without M1a, M1b, or M1c sites of disease

Not recorded or unspecified

 M1d(0)

Normal

 M1d(1)

Elevated

  1. Suffixes for M category: (0) LDH not elevated, (1) LDH elevated. No suffix is used if LDH is not recorded or is unspecified
  2. Used with permission of the American Joint Committee on Cancer (AJCC), Chicago, Illinois. The original and primary source for this information is the AJCC Cancer Staging Manual, 8th edition (2017) published by Springer International Publishing ref. [24]
Back to article page