Collaborative Stage

Note 1: If there is a discrepancy between the Clark level and the pathologic description of extent (invasion into the layers of the dermis), use the higher (more extensive) code.
Note 2: Satellite lesions/nodules or in-transit metastases are coded under CS Lymph Nodes.
Note 3: Ulceration of the melanoma is coded in Site-Specific Factor 2.

^ For CS Extension codes 100-300, 400-800, and 999 ONLY, the T category for AJCC 7staging is assigned based on the values of CS Site-Specific Factor 1, Measured Thickness, CS Site-Specific Factor 2, Ulceration, and for certain cases CS Site-Specific Factor 7, Primary Tumor Mitotic Count/Rate, as shown in the Thickness, Ulceration AJCC 7 Table.
^^For CS Extension codes 310-380 ONLY, the T category for AJCC 7 staging is assigned based on the values of CS Extension, CS Site-Specific Factor 1, Measured Thickness, CS Site-Specific Factor 2, Ulceration, and for certain cases CS Site-Specific Factor 7, Primary Tumor Mitotic Count/Rate, as shown in the ExtensionThickness Ulceration T Category AJCC 7 table.
* For CS Extension codes 100-300, 400-800, and 999 ONLY, the T category for AJCC 6 staging is assigned based on the values of CS Site-Specific Factor 1, Measured Thickness, and CS Site-Specific Factor 2, Ulceration, as shown in the Thickness Ulceration AJCC 6 Table.
**For CS Extension codes 310-380 ONLY, the T category for AJCC 6 staging is assigned based on the values of CS Extension, CS Site-Specific Factor 1, Measured Thickness, and CS Site-Specific Factor 2, Ulceration, as shown in the Extension, Thickness, Ulceration, T Category AJCC 6 Table.

Code	Description	TNM 7 Map	TNM 6 Map	SS77 Map	SS2000 Map
000	In situ, intraepidermal, intraepithelial, noninvasive (Basement membrane of the epidermis is intact) Clark level I	Tis	Tis	IS	IS
100	Papillary dermis invaded Clark level II	^	*	L	L
200	Papillary-reticular dermal interface invaded Clark level III	^	*	L	L
300	Reticular dermis invaded Clark level IV	^	*	L	L
310	Stated as T1a with no other information on extension	^^	**	L	L
315	Stated as T1b with no other information on extension	^^	**	L	L
320	Stated as T1 [NOS] with no other information on extension	^^	**	L	L
330	Stated as T2a with no other information on extension	^^	**	L	L
335	Stated as T2b with no other information on extension	^^	**	L	L
340	Stated as T2 [NOS] with no other information on extension	^^	**	L	L
350	Stated as T3a with no other information on extension	^^	**	L	L
355	Stated as T3b with no other information on extension	^^	**	L	L
360	Stated as T3 [NOS] with no other information on extension	^^	**	L	L
370	Stated as T4a with no other information on extension	^^	**	L	L
375	Stated as T4b with no other information on extension	^^	**	L	L
380	Stated as T4 [NOS] with no other information on extension	^^	**	L	L
400	Skin/dermis, NOS Localized, NOS	^	*	L	L
500	Subcutaneous tissue invaded (through entire dermis) Clark's level V	^	*	L	RE
800	Further contiguous extension: Underlying cartilage, bone, skeletal muscle	^	*	D	D
950	No evidence of primary tumor	T0	T0	U	U
999	Unknown; extension not stated Primary tumor cannot be assessed Not documented in patient record	^	*	U	U

CS Extension