Collaborative Stage

Note 1: AJCC considers all anaplastic carcinomas to be T4.
Note 2: AJCC considers "in situ carcinoma of thyroid gland" an impossible diagnosis. Any case so coded will be mapped to an unknown AJCC stage, in situ Summary Stage.
Note 3: Use code 300 for localized tumor ONLY if no information is available to assign codes 000, 100, 200, 400, 405, 410, 415, or 420.
Note 4: Use code 405, 410, 415, 420, 490, 810, or 815 if the physician's assignment of T category is the ONLY information available about the extent of the tumor. Extension codes 405, 410, 415, 420, and 490 are not compatible with anaplastic carcinomas of thyroid.

^ For Extension codes 100-550 ONLY, the T category for AJCC 7th Edition staging is assigned based on the value of CS Tumor Size and/or CS Extension as shown in the Extension Size Table AJCC 7 for all histologies except 8020, 8021, 8030, 8031, and 8032, or any other histology with grade equal 4. For these histologies or grade 4, the T category is assigned based on the value of CS Extension as shown in the Histology Grade Extension AJCC Table.
* For Extension codes 100-550 ONLY, the T category for AJCC 6th Edition staging is assigned based on the value of CS Tumor Size and/or CS Extension as shown in the Extension Size Table AJCC 6 for all histologies except 8020, 8021, 8030, 8031, and 8032, or any other histology with grade equal 4. For these histologies or grade 4, the T category is assigned based on the value of CS Extension as shown in the Histology Grade Extension AJCC Table.
** For Extension code 560 ONLY, the value for SS1977 and SS2000 is assigned based on the value of histology and grade as shown in the Histology Grade Extension Summary Stage Table.

Code	Description	TNM 7 Map	TNM 6 Map	SS77 Map	SS2000 Map
000	In situ; non-invasive	TX	TX	IS	IS
100	Single invasive tumor confined to thyroid	^	*	L	L
200	Multiple foci confined to thyroid	^	*	L	L
300	Localized, NOS	^	*	L	L
400	Into thyroid capsule, but not beyond	^	*	L	L
405	Stated as T1a with no other information on extension	^	*	L	L
410	Stated as T1b with no other information on extension	^	*	L	L
415	Stated as T1 [NOS] with no other information on extension	^	*	L	L
420	Stated as T2 with no other information on extension	^	*	L	L
450	Minimal extrathyroid extension including: Strap muscle(s): Omohyoid Sternohyoid Sternothyroid Thyrohyoid	^	*	RE	RE
480	Pericapsular soft/connective tissue	^	*	RE	RE
490	Stated as T3 with no other information on extension	^	*	L	L
500	Parathyroid Nerves: Recurrent laryngeal Vagus	^	*	RE	RE
520	Cricoid cartilage Esophagus Larynx Sternocleidomastoid muscle	^	*	RE	RE
550	Trachea	^	*	D	D
560	Stated as T4a with no other information on extension	T4a	T4a	**	**
600	Thyroid cartilage Tumor is described as "FIXED to adjacent tissues"	T4b	T4b	RE	RE
620	Blood vessel(s) (major): Carotid artery Jugular vein Thyroid artery or vein	T4b	T4b	RE	RE
650	(600 or 620) + 550 (Any structures in code 600 or 620 + Trachea)	T4b	T4b	D	D
700	Bone Skeletal muscle, other than strap or sternocleidomastoid muscle	T4b	T4b	D	D
720	OBSOLETE DATA CONVERTED V0200 See code 550 Trachea	ERROR	ERROR	ERROR	ERROR
800	Further contiguous extension: Mediastinal tissues Prevertebral fascia	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 Primary tumor cannot be assessed Not documented in patient record	TX	TX	U	U

Thyroid

CS Extension