GumOther - CS Extension

Note 1: Superficial erosion alone of bone/tooth socket by gingival primary is not sufficient to code as bone involvement (code 700).
Note 2: Periosteum is a fibrous membrane that wraps the outer surface of bones. Mucoperiosteum is a compound structure of mucous membrane and periosteum. Cortical bone is the dense compact outer layer of bone. Trabecular, cancellous, or spongy bone (spongiosa) is a porous network of tissue filling the interior of bone, decreasing weight and allowing room for blood vessels and marrow.
Note 3: AJCC assigns the T category based on size for involvement of cortical bone. Involvement through cortical bone is required for assignment of T4a.
Note 4: The assignment of T1, T2 , and T3 categories for tumors of the lip and oral cavity is based on tumor size. A physician's statement of the T category may be used to code 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, other than the physician's statement of the T category. Use codes 405, 410, 415, 775, 810, or 815 as appropriate to code CS Extension based on a statement of T when no other extension information is available.
Note 5: Use code 300 for localized tumor only if no information is available to assign code 100, 405, 410, or 415.

^ For CS Extension codes 100-650 ONLY, the T category for AJCC 7 staging is assigned based on the value of CS Tumor Size as shown in the Extension Size Table for this schema.
* For CS Extension codes 100-650 ONLY, the T category for AJCC 6 staging is assigned based on the value of CS Tumor Size, as shown in the Extension Size Table for this schema.

Code	Description	TNM 7 Map	TNM 6 Map	SS77 Map	SS2000 Map
000	In situ, intraepithelial, noninvasive	Tis	Tis	IS	IS
100	Invasive tumor confined to lamina propria (mucoperiosteum) (stroma)	^	*	L	L
300	Localized, NOS	^	*	L	L
405	Stated as T1 with no other information on extension	^	*	L	L
410	Stated as T2 with no other information on extension	^	*	L	L
415	Stated as T3 with no other information on extension	^	*	L	L
500	Buccal mucosa (inner cheek) Labial mucosa (inner lip), lip Tongue (mucosa)	^	*	RE	RE
535	Cartilage of mandible or maxilla Cortical bone of mandible or maxilla Mandible, NOS Maxilla, NOS Cartilage, NOS Cortical bone, NOS Bone, NOS	^	*	RE	RE
550	Facial muscle, NOS Subcutaneous soft tissue of face	^	*	RE	RE
600	Lateral pharyngeal wall Tonsillar pillars and fossae Tonsils	^	*	RE	RE
650	Soft palate including uvula	^	*	RE	RE
720	Deep (extrinsic) muscle of tongue: Genioglossus Hyoglossus Palatoglossus Styloglossus	T4a	T4a	RE	RE
725	Trabecular bone: Mandible Maxilla Palatine bone	T4a	T4a	RE	RE
760	Skin of face	T4a	T4a	D	D
770	Maxillary sinus (antrum)	T4a	T4a	D	D
775	Stated as T4a with no other information on extension	T4a	T4a	RE	RE
788	Specified bone (Other than maxilla, mandible, or bones in codes 795 and 805)	T4b	T4b	D	D
790	OBSOLETE DATA CONVERTED V0200 See code 805 Skull	ERROR	ERROR	ERROR	ERROR
795	Masticator space Pterygoid plates	T4b	T4b	D	D
800	OBSOLETE DATA RETAINED V0200 Further contiguous extension, including: Masticator space Pterygoid Plates Skull base Encases internal carotid artery	ERROR	T4b	D	D
805	Further contiguous extension including: Base of skull Internal carotid artery (encased) Skull	T4b	T4b	D	D
810	Stated as T4b with no other information on extension	T4b	T4b	D	D
815	Stated as T4 [NOS] with no other information on extension	T4NOS	T4NOS	RE	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