CS Extension: Stomach

Note 1: INTRALUMINAL or INTRAMURAL extension to esophagus and duodenum is classified by the depth of greatest invasion in any of these sites, including stomach. (For extension to esophagus or duodenum via serosa, see code 60.)

Note 2: If the diagnosis states "linitis plastica" and no other information regarding extension is available, use code 35.

Code Description TNM SS77 SS2000
00 In situ; noninvasive; intraepithelial Tis IS IS
05 (Adeno)carcinoma in a polyp, noninvasive Tis IS IS
10 Invasive tumor confined to mucosa, NOS (including intramucosal, NOS) T1 L L
11 Invades lamina propria T1 L L
12 Invades muscularis mucosae T1 L L
  • Confined to head of polyp
  • Extension to stalk
T1 L L
14 Confined to stalk of polyp T1 L L
15 Tumor in polyp, NOS T1 L L
16 Invades submucosa (superficial invasion) T1 L L
20 Invades into but not through muscularis propria T2a L L
  • Localized, NOS
  • Implants inside stomach
T1 L L
35 Linitis plastica (see Note 2) and no other information regarding extension is available. T2a RE L
  • Invasion through muscularis propria or muscularis, NOS
  • Extension through wall, NOS
  • Perimuscular tissue invaded
  • Subserosal tissue/(sub)serosal fat invaded
T2b L L
45 Extension to adjacent (connective) tissue without perforation of visceral peritoneum:
  • Gastric artery
  • Ligaments:
  • Gastrocolic
  • Gastrohepatic
  • Gastrosplenic
  • Omentum, NOS
  • Greater
  • Lesser
  • Perigastric fat
50 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 T3 RE RE
55 (45) + (50) T3 RE RE
  • Diaphragm
  • Duodenum via serosa or NOS
  • Esophagus via serosa
  • Ileum
  • Jejunum
  • Liver
  • Pancreas
  • Small intestine, NOS
  • Spleen
  • Transverse colon (including flexures)
  • Abdominal wall
  • Adrenal gland
  • Kidney
  • Retroperitoneum
T4 D D

Further contiguous extension

T4 D D
95 No evidence of primary tumor T0 U U
  • Unknown extension
  • Primary tumor cannot be assessed
  • Not documented in patient record
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