Skin - Melanocytic tumor
Miscellaneous
Staging of melanomas

Author: Christopher Hale, M.D. (see Authors page)

Revised: 16 February 2017, last major update May 2013

Copyright: (c) 2002-2017, PathologyOutlines.com, Inc.

PubMed Search: Staging melanomas skin

Cite this page: Staging of melanomas. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/skintumormelanocyticmelanomastaging.html. Accessed February 23rd, 2017.
Staging / Staging classifications

Prior staging systems
  • AJCC 2002 system more complex, but no better predictive ability than AJCC 1997 (Cancer 2006;106:163)

Primary tumor (T)
  • TX: primary tumor cannot be assessed (e.g., curettaged or regressed melanoma)
  • T0: no evidence of primary tumor
  • Tis: melanoma in situ
  • T1: melanoma 1.0 mm or less in thickness
  • T1a: melanoma 1.0 mm or less in thickness, without ulceration and mitosis < 1/mm²
  • T1b: melanoma 1.0 mm or less in thickness, with ulceration or mitosis ≥ 1/mm²
  • T2: melanoma 1.01 - 2.0 mm in thickness
  • T2a: melanoma 1.01 - 2.0 mm in thickness, without ulceration
  • T2b: melanoma 1.01 - 2.0 mm in thickness, with ulceration
  • T3: melanoma 2.01 - 4.0 mm in thickness
  • T3a: melanoma 2.01 - 4.0 mm in thickness, without ulceration
  • T3b: melanoma 2.01 - 4.0 mm in thickness, with ulceration
  • T4: melanoma greater than 4.0 mm in thickness
  • T4a: melanoma greater than 4.0 mm in thickness, without ulceration
  • T4b: melanoma greater than 4.0 mm in thickness, with ulceration

Note:
  • Ulceration means absence of intact epidermis overlying the primary melanoma, as assessed by histologic examination

Regional lymph nodes (N)
  • NX: regional lymph nodes cannot be assessed (e.g., previously removed for another reason)
  • N0: no regional lymph node metastasis
  • N1: metastasis in one lymph node
  • N1a: micrometastasis
  • N1b: macrometastasis
  • N2: metastasis in 2 - 3 regional nodes
  • N2a: micrometastasis
  • N2b: macrometastasis
  • N2c: satellite or in-transit metastasis without nodal metastasis
  • N3: metastasis in four or more regional nodes, or matted metastatic nodes, or in-transit metastasis or satellite(s) with metastasis in regional node(s)

  • Micrometastases are diagnosed after sentinel lymph node biopsy and completion lymphadenectomy (if performed)
  • Macrometastases are defined as clinically detectable nodal metastases confirmed by therapeutic lymphadenectomy or when nodal metastasis exhibits gross extracapsular extension
  • Satellite metastases: defined arbitrarily as intralymphatic metastases occurring within 2 cm of the primary melanoma
  • In transit metastases: defined arbitrarily as intralymphatic metastases occurring more than 2 cm from the primary melanoma but before the first echelon of regional lymph nodes

Note:
  • HMB45 or MelanA positive isolated cells in sentinel nodes appear to have no prognostic significance, at least short term (Am J Surg Pathol 2007;31:1175)

Distant Metastases (M)
  • M0: no detectable evidence of distant metastases
  • 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 associated with an elevated serum lactic dehydrogenase (LDH)

Clinical stage grouping
0:TisN0M0
IA:T1aN0M0
IB:T1b / T2aN0M0
IIA:T2b / T3aN0M0
IIB:T3b / T4aN0M0
IIC:T4bN0M0
III:any TN1 - 3M0
IV:any Tany NM1

  • Clinical staging includes microstaging of the primary melanoma and clinical / radiologic examination for metastases
  • By convention, it should be used after complete excision of the primary melanoma with clinical assessment for regional and distant metastases

Pathologic stage grouping
I:TisN0M0
IA:T1aN0M0
IB:T1b / T2aN0M0
IIA:T2b / T3aN0M0
IIB:T3b / T4aN0M0
IIC:T4bN0M0
IIIA:T1 - 4aN1a / N2aM0
IIIB:T1 - 4bN1a / N2aM0orT1 - 4aN1b / N2b / N2cM0
IIIC:T1 - 4bN1b / N2b / N2cM0orany TN3M0
IV:any Tany NM1

  • Pathologic staging includes microstaging of the primary melanoma and pathologic information about the regional lymph nodes after partial or complete lymphadenectomy
  • Pathologic Stage 0 or Stage IA patients are the exception; they do not require pathologic evaluation of their lymph nodes