Collaborative Stage

Note 1: AJCC 7th Edition T1 and T2 categories are based on size and high risk features and not depth of invasion or extension. AJCC 7th Edition includes a T3 category for head and neck skin primaries only.
Note 2: In the case of multiple simultaneous tumors, code the tumor with the greatest extension.
Note 3: Skin ulceration does not alter the AJCC T category.
Note 4: The assignment of the T1 category for cutaneous squamous cell carcinomas with one or no high-risk features is based on tumor size. A physician's statement of the T1 category may be used to code both CS Tumor Size and/or CS Extension if this is the only information in the medical record regarding one or both of these fields. However the two fields are coded independently; for example, the record may document size but not extension. Use codes 510, 520, 600, and 810 as appropriate to code CS Extension based on a statement of T when no other extension information is available.
Note 5: Use code 400 (Localized, NOS) when no further information is available to assign code 100, 500, 510, or 520.

^ For CS Extension codes 100, 400, 500, 510, and 550 ONLY, the T category for AJCC 7 staging is assigned based on the values of CS Tumor Size and CS Site-Specific Factor 12, High Risk Features, as shown in the Extension Size High Risk Table for this schema.
* For CS Extension codes 100, 400, 500 and 510 ONLY, the T category for AJCC 6th Edition is assigned based on value of CS Tumor Size as shown in the Extension Size AJCC 6 Table for this schema.

Code	Description	TNM 7 Map	TNM 6 Map	SS77 Map	SS2000 Map
000	In situ, intraepidermal, intraepithelial, noninvasive; Bowen disease	Tis	Tis	IS	IS
100	Lesion(s) confined to dermis	^	*	L	L
400	Localized, NOS	^	*	L	L
500	Subcutaneous tissue (through entire dermis)	^	*	L	L
510	Stated as T1 with no other information on extension	^	*	L	L
520	Stated as T2 with no other information on extension	T2	T2	L	L
550	Underlying cartilage and/or skeletal muscle	^	T4	D	RE
600	For skin of head and neck primaries only: Maxilla Mandible Orbital bone Temporal bone Stated as T3 with no other information on extension	T3	T4	D	RE
700	OBSOLETE DATA RETAINED V0200 Invasion of cartilage, bone, skeletal muscle reclassified in AJCC 7th Edition See codes 550, 600, 710, and 750 Underlying cartilage, bone, skeletal muscle	ERROR	T4	D	RE
710	For skin of head and neck primaries only: Direct or perineural invasion of skull base	T4	T4	D	RE
750	Bone (other than in code 600 or 710): Axial or appendicular skeleton	T4	T4	D	RE
800	Further contiguous extension	T4	T4	D	D
810	Stated as T4 with no other information on extension	T4	T4	D	RE
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	TX	TX	U	U

CS Extension