Table 1 AJCC melanoma TNM classification (revised 2002)⁷ and stage groupings for cutaneous melanomas

T classification	Thickness (mm)	Ulceration status
T₁	≤1.0	a: W/o ulceration and level II or III
		b: With ulceration or level IV or V
T₂	1.01–2.00	a: W/o ulceration
		b: With ulceration
T₃	2.01–4.0	a: W/o ulceration
		b: With ulceration
T₄	>4.0	a: W/o ulceration
		b: With ulceration

N classification	Number of metastatic nodes	Nodal metastatic mass
N₁	One node	a: Micrometastasis^a
		b: Macrometastasis^b
N₂	Two to three nodes	a: Micrometastasis^a
		b: Macrometastasis^b
		c: In transit met(s)/satellite(s) without metastatic nodes
N₃	Four or more metastatic nodes, or matted nodes, or in transit met(s)/satellite(s) and metastatic node(s)

M classification	Site	Serum LDH
M_1a	Distant skin, SQ or nodal mets	Normal
M_1b	Lung metastases	Normal
M_1c	All other visceral metastases	Normal
	Any distant metastasis	Elevated

Stage groupings for cutaneous melanomas
Clinical staging ^c				Pathologic staging ^d
0	Tis	N0	M0	0	Tis	N0	M0
IA	T1a	N0	M0	IA	T1a	N0	M0
IB	T1b	N0	M0	IB	T1b	N0	M0
	T2a	N0	M0		T2a	N0	M0
IIA	T2b	N0	M0	IIA	T2b	N0	M0
	T3a	N0	M0		T3a	N0	M0
IIB	T3b	N0	M0	IIB	T3b	N0	M0
	T4a	N0	M0		T4a	N0	M0
IIC	T4b	N0	M0	IIC	T4b	N0	M0
III	Any T	Any N	M0	IIIA	T1-4a	N1a	M0
					T1-4a	N2a	M0
				IIIB	T1-4b	N1a	M0
					T1-4b	N2a	M0
					T1-4a	N1b	M0
					T1-4a	N2b	M0
					T1-4a/b	N2c	M0
				IIIC	T1-4b	N1b	M0
					T1-4b	N2b	M0
					T1-4b	N2c	M0
					Any T	N3	M0
IV	Any T	Any N	Any M	IV	Any T	Any N	Any M

^aMicrometastases are diagnosed after elective or sentinel lymphadenectomy.
^bMacrometastases are defined as clinically detectable nodal metastases confirmed by therapeutic lymphadenectomy or when nodal metastasis exhibits gross extracapsular extension.
^cClinical staging includes microstaging of the primary melanoma and clinical/radiologic evaluation for metastases. By convention, it should be used after complete excision of the primary melanoma with clinical assessment for regional and distant metastases.
^dPathologic staging includes microstaging of the primary melanoma and pathologic information concerning regional lymph nodes after partial or complete lymphadenectomy. Patients with pathologic Stage 0 or Stage IA disease are the exception; they do not require pathologic evaluation of their lymph nodes.

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