GISTStomach - CS Extension

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: Intraluminal or intramural extension to esophagus and duodenum is classified by the depth of greatest invasion in any of these sites, including stomach.
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 340, 390, 395, and 398 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.

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

Code	Description	TNM 7 Map	TNM 6 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, noninvasive, in a polyp	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 Invades lamina propria	^	NA	L	L
120	OBSOLETE DATA RETAINED AND REVIEWED V0203 See codes 155 and 165 Invades muscularis mucosae	^	NA	L	L
130	OBSOLETE DATA RETAINED AND REVIEWED V0203 See codes 155 and 165 Confined to head of polyp Extension to stalk 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	Invasive tumor in 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 Invades submucosa (superficial invasion)	^	NA	L	L
165	Tumor invades through submucosa and muscularis mucosae to involve mucosa	^	NA	L	L
200	OBSOLETE DATA RETAINED AND REVIEWED V0203 See codes 155 and 165 Invades into but not through muscularis propria	^	NA	L	L
300	Implants inside stomach Localized, NOS	^	NA	L	L
340	Stated as T1 with no other information on extension	^	NA	L	L
350	OBSOLETE DATA RETAINED V0200 Linitis plastica and no other information regarding extension is available	ERROR	NA	RE	L
390	Stated as T2 with no other information on extension	^	NA	L	L
395	Stated as T3 with no other information on extension	^	NA	L	L
398	Stated as T4 with no other information on extension	^	NA	L	L
400	Invasion through muscularis propria or muscularis, NOS Extension through wall, NOS Perimuscular tissue invaded Subserosal tissue/(sub)serosal fat invaded Note: In V0203 ONLY, code 400 had a different meaning, but the original description of the code has been restored in V0204.	^	NA	L	L
440	Intraluminal extension to esophagus or duodenum	^	NA	RE	L
450	Extension to adjacent (connective) tissue WITHOUT perforation of visceral peritoneum: Gastric artery Ligaments: Gastrocolic Gastrohepatic Gastrosplenic Omentum, NOS: Greater Lesser Perigastric fat	^	NA	RE	RE
458	Fat, NOS	^	NA	RE	RE
480	OBSOLETE DATA CONVERTED V0203 See code 395 Stated as T3 with no other information on extension	ERROR	ERROR	ERROR	ERROR
490	OBSOLETE DATA CONVERTED V0203 See code 398 Stated as T4 with no other information on extension	ERROR	ERROR	ERROR	ERROR
500	Invasion of/through serosa (mesothelium) (tunica serosa) (visceral peritoneum), including perforation of visceral peritoneum covering the gastric ligaments or the omentum WITHOUT invasion of adjacent structures	^	NA	RE	RE
550	500 + 450	^	NA	RE	RE
560	Invasion of/through serosa with invasion of/through mucosa	^	NA	RE	RE
600	OBSOLETE DATA RETAINED AND REVIEWED V0203 See codes 610 and 650 Diaphragm Duodenum via serosa or NOS Esophagus via serosa Ileum Jejunum Liver Pancreas Small intestine, NOS Spleen Transverse colon/mesocolon (including flexures) Celiac axis Aorta	^	NA	RE	RE
610	Diaphragm Duodenum via serosa Duodenum, NOS Esophagus via serosa Ileum Jejunum Liver Pancreas Small intestine, NOS Spleen Transverse colon/mesocolon (including flexures)	^	NA	RE	RE
650	Aorta Celiac axis	^	NA	D	D
700	Abdominal wall Adrenal gland Kidney Retroperitoneum	^	NA	D	D
800	Further contiguous extension	^	NA	D	D
950	No evidence of primary tumor	T0	NA	U	U
999	Unknown; extension not stated Primary tumor cannot be assessed Not documented in patient record	TX	NA	U	U