Collaborative Stage

Note 1: AJCC does not include a Tis category for gastrointestinal stromal tumors (GIST). Any case with a CS Extension code of 000 is mapped to TX for AJCC 7 stage and in situ Summary Stage.
Note 2: Give priority to coding depth of invasion or spread outside the small intestine for tumor with intraluminal or lateral extension to adjacent segment(s) of small intestine.
Note 3: The assignment of T categories for GISTs 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 170, 210, 250, and 270 as appropriate to code CS Extension based on a statement of T when no other extension information is available.
Note 4: Use code 150 only if GIST is described as arising in a polyp. Do not use this code for GIST described as arising in the wall of the appendix and extending into the lumen with a polypoid appearance.
Note 5: Use code 300 for localized cases only if no information is available to assign a more specific code.
Note 6: Adherence to the liver capsule is not considered distant metastasis. Use code 570 for any adherence to the liver capsule.

For CS Extension codes 100-800 ONLY, the T category for AJCC 7 staging is assigned based on the value of CS Tumor Size, as shown in the Extension Size AJCC 7 Table for this site.

Code	Description	TNM 7th Map	TNM 6th Map	SS77 Map	SS2000 Map
000	In situ, intraepithelial, noninvasive	TX	NA	IS	IS
050	OBSOLETE DATA RETAINED AND REVIEWED V0203 See code 000 (Adeno)carcinoma in a polyp, noninvasive	TX	NA	IS	IS
100	OBSOLETE DATA RETAINED AND REVIEWED V0203 See codes 155 and 165 Invasive tumor confined to mucosa, NOS, including intramucosal, NOS	^	NA	L	L
110	OBSOLETE DATA RETAINED AND REVIEWED V0203 See codes 155 and 165 Invasion of lamina propria	^	NA	L	L
120	OBSOLETE DATA RETAINED AND REVIEWED V0203 See code 155 and 165 Invasion of muscularis mucosae	^	NA	L	L
130	OBSOLETE DATA RETAINED AND REVIEWED V0203 See codes 155 and 165 Confined to head of polyp	^	NA	L	L
140	OBSOLETE DATA RETAINED AND REVIEWED V0203 See codes 155 and 165 Confined to stalk of polyp	^	NA	L	L
150	Invasion of polyp, NOS	^	NA	L	L
155	Tumor confined to muscular wall	^	NA	L	L
160	OBSOLETE DATA RETAINED AND REVIEWED V0203 See codes 155 and 165 Invasion of submucosa (superficial invasion)	^	NA	L	L
165	Tumor invades through submucosa and muscularis mucosae to involve mucosa	^	NA	L	L
170	Stated as T1 with no other information on extension	^	NA	L	L
200	OBSOLETE DATA RETAINED AND REVIEWED V0203 See code 155 and 165 Muscularis propria invaded	^	NA	L	L
210	Stated as T2 with no other information on extension	^	NA	L	L
250	Stated as T3 with no other information on extension	^	NA	L	L
270	Stated as T4 with no other information on extension	^	NA	L	L
300	Intraluminal spread to other segments of small intestine or cecum (See Note 2) Localized, NOS	^	NA	L	L
400	Invasion through muscularis propria or muscularis, NOS Extension through wall, NOS Subserosal tissue/(sub) serosal fat invaded Transmural, NOS	^	NA	L	L
410	OBSOLETE DATA CONVERTED V0203 See code 250 Stated as T3, NOS	ERROR	ERROR	ERROR	ERROR
420	OBSOLETE DATA CONVERTED V0203 See code 458 Fat, NOS	ERROR	ERROR	ERROR	ERROR
450	Adjacent connective tissue Mesentery, including mesenteric fat, invaded less than or equal to 2 cm in depth or invaded, NOS Nonperitonealized perimuscular tissue invaded less than or equal to 2 cm in depth or invaded, NOS Retroperitoneum invaded less than or equal to 2 cm in depth or NOS	^	NA	RE	RE
458	Fat, NOS	^	NA	RE	RE
500	Invasion of/through serosa (mesothelium) (tunica serosa) (visceral peritoneum)	^	NA	L	RE
550	500 + (420 or 450) Invasion of/through serosa plus invasion of structures in codes 420 or 450	^	NA	RE	RE
560	Invasion of/through serosa with invasion of/through mucosa	^	NA	RE	RE
600	For duodenum primary only: Ampulla of Vater Diaphragm Extrahepatic bile duct(s) Gallbladder Pancreas Pancreatic duct	^	NA	RE	RE
650	For duodenum primary only: Blood vessel(s), major: Aorta Gastroduodenal artery Portal vein Renal vein Superior mesenteric artery or vein Vena cava Greater omentum Hepatic flexure Kidney, NOS Kidney, right Liver, NOS Liver, quadrate lobe Liver, right lobe Omentum, NOS Transverse colon Ureter, right For jejunum or ileum primaries only: Colon, including appendix	^	NA	RE	RE
660	For duodenum primary only: Stomach	^	NA	RE	RE
670	Abdominal wall Mesentery invaded greater than 2 cm in depth Non-peritonealized perimuscular tissue invaded greater than 2 cm in depth Retroperitoneum invaded greater than 2 cm in depth	^	NA	RE	RE
680	Other segments of the small intestine via serosa	^	NA	RE	RE
690	OBSOLETE DATA CONVERTED V0203 See code 270 Stated as T4, NOS	ERROR	ERROR	ERROR	ERROR
700	For jejunum or ileum primary only: Bladder Fallopian tube(s) Ovary(ies) Uterus	^	NA	D	D
800	Further contiguous extension	^	NA	D	D
950	No evidence of primary tumor	T0	NA	U	U
999	Unknown extension Primary tumor cannot be assessed Not documented in patient record	TX	NA	U	U

GISTSmallIntestine

CS Extension