Normal

• portions
  • cardia: mucinous glands
  • fundus: oxyntic mucosa
  • body: oxyntic mucosa
  • antrum: mucinous glands
  • pylorus: mucinous glands
  • greater curvature: attaches to omentum and transverse colon mesentery
  • lesser curvature: attaches to liver by gastrohepatic ligament
• layers
  • mucosa
    • foveolar pits
      • shorter in body (1/4 thickness)
      • longer in cardia and antrum (1/2 thickness)
      • tall columnar mucinous lining
      • basal nuclei
      • same epithelium throughout stomach
    • neck: base of foveola, contains mucous neck cells, slightly larger nuclei than foveola
    • deep glands: oxyntic glands in body and fundus, mucinous glands elsewhere
    • lamina propria: scattered mononuclear cells are normal. Too much is chronic gastritis.
    • muscularis mucosa
  • submucosa
    • can have fat
  • muscularis propria
    • inner oblique
    • middle circular
    • Auerbach plexus
    • outer longitudinal
  • subserosa
  • serosa
• gland types
  • oxyntic glands
    • contains parietal and chief cells
  • mucinous glands
    • bubbly mucinous cytoplasm
    • basal nuclei
• cell types
  • parietal cell
    • pink, central nuclei
    • makes acid and intrinsic factor
    • more prominent in upper mucosa
  • chief cell
    • makes enzymes
    • blue, basal nuclei, cuboidal-columnar
    • more prominent in deeper mucosa
  • endocrine cells
    • gastrin G cells in antrum
    • histamine ECL cells in body
• Signout
  • Benign gastric mucosa
  • No dysplasia, intestinal metaplasia, or gastritis identified
  • No H. Pylori identified on H&E

Approach

• epithelial abnormalities
  • dysplasia: HG present? vs reactive
  • carcinoma
  • intestinal metaplasia
  • foveolar hyperplasia
  • PPI effect
• stromal infiltrate
  • soft tissue tumor
  • hematolymphoid
• gastritis
• clinical cues
  • H. Pylori, gastritis
  • polyps: fundic gland polyp, hyperplastic polyp, others
  • watermelon stomach/strips on endoscopy: GAVE

polyp

gastritis

neoplasm

Other

• foveolar hyperplasia
• PPI effect
• reactive gastropathy
• therapy induced gastropathy
• gastric antral vascular ectasia
• portal hypertensive gastropathy
• peptic ulcer
• Dieulafoy lesion
• Kayexalate crystals
• bariatric surgery
• amyloidosis
• xanthoma
• pseudo-signet ring cells
• gastric mucosal calcinosis

Metaplasia

• intestinal metaplasia
• pyloric metaplasia
• paneth cell metaplasia
• pancreatic metaplasia
• pancreatic heterotopia

TNM (useful for grossing)

• Carcinoma
  • Tis: in situ
  • T1a: lamina propria or muscularis mucosa invasion
  • T1b: submucosa invasion
  • T2: muscularis propria invasion
  • T3: subserosa invasion
  • T4a: serosa perforation
  • T4b: adjacent structure invasion
  • N1: 1-2 regional nodes
  • N2: 3-6 regional nodes
  • N3a: 7-15 regional nodes
  • N3b: 16+ regional nodes
• Carcinoid
  • Tis: in situ, < 0.5 mm, mucosa confined
  • T1: 0.5 mm to 1 cm, submucosa confined
  • T2: > 1 cm or muscularis propria invasion
  • T3: subserosa invasion
  • T4: serosa perforation or adjacent structure invasion
• GIST
  • T1: <= 2 cm
  • T2: > 2 cm and <= 5 cm
  • T3: > 5 cm and <= 10 cm
  • T4: > 10 cm
  • Grading
    • low mitotic rate: <= 5 mitosis per 50 hpf
    • high mitotic rate: > 5 mitosis per 50 hpf

Staging

• Carcinoma
  • 0: Tis
  • IA: T1
  • IB: T2 or T1 N1
  • IIA: T3, T2 N1 or T1 N2
  • IIB: T4a, T3 N1, T2 N2, or T1 N3
  • IIIA: T4a N1, T3 N2, or T2 N3
  • IIIB: T4b N0-1, T4a N2, or T3 N3
  • IIIC: T4b N2-3 or T4a N3
  • IV: M1
• Carcinoid
  • 0: Tis
  • I: T1
  • IIA: T2
  • IIB: T3
  • IIIA: T4
  • IIIB: N1
  • IV: M1
• GIST (gastric and omental)
  • IA: T1-2
  • IB: T3
  • II: T4 or T1-2 and high mitosis
  • IIIA: T3 and high mitosis
  • IIIB: T4 and high mitosis
  • IV: N1 or M1