Collaborative Stage

Note 1: If there is a discrepancy between the Clark level and the pathologic description of extent, 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 Extension codes 100-800 and 999 ONLY, the T category for AJCC 7th Edition staging 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 and Ulceration AJCC 7 table.
* For Extension codes 100-800, and 999 ONLY, the T category for AJCC 6th Edition 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 and Ulceration AJCC 6 table.

Code	Description	TNM 7 Map	TNM 6 Map	SS77 Map	SS2000 Map
000	In situ: noninvasive; intraepidermal Clark's level I Basement membrane of the epidermis is intact	Tis	Tis	IS	IS
100	Papillary dermis invaded Clark's level II	^	*	L	L
200	Papillary-reticular dermal interface invaded Clark's level III	^	*	L	L
300	Reticular dermis invaded Clark's level IV	^	*	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 Primary tumor cannot be assessed (e.g., shave biopsy or regressed melanoma) Not documented in patient record	^	*	U	U

CS Extension