Stomach pathology

• What is the definition of gastritis?


  Inflammation of gastric mucosa
• What are the two types of gastritis?

  • Acute Gastritis
  • Chronic Gastritis
• What characterizes acute gastritis?

  Transient mucosal acute inflammation
• What are common associations with acute gastritis?

  • Heavy use of NSAIDs
  • Excessive alcohol consumption
  • Heavy smoking
  • Chemotherapeutic drugs
  • Uremia
  • Systemic infections (e.g., Salmonella, CMV)
  • Severe stress (trauma, burns, surgery)
  • Ischemia & shock
  • Suicidal ingestion of corrosives
  • Gastric irradiation
  • Nasogastric intubation
• What is the pathogenesis of acute gastritis?


  It is poorly understood but involves several influences.
• What are the influences thought to be operative in acute gastritis pathogenesis?

  • Increased acid secretion with back diffusion
  • Decreased production of HCO-3 buffer
  • Reduced blood flow
  • Disruption of adherent mucus layer
  • Direct damage to epithelium
  • Regurgitation of bile acids from duodenum
  • Inadequate synthesis of PGs
  • Idiopathic gastritis
• What are the morphological features of mild acute gastritis?


  • Mucosal hyperemia
  • Lamina propria edema & congestion
  • Surface epithelium intact
  • Scattered intraepithelial & intraluminal neutrophils
• What are the morphological features of severe acute gastritis?

  • Mucosal erosion & hemorrhage
  • Loss of surface epithelium
  • Marked inflammatory cell infiltrate
  • Fibrinous purulent exudate into lumen
  • Hemorrhage with punctate dark spots
• What is acute erosive hemorrhagic gastritis?


  Concurrent erosion and hemorrhage in the gastric mucosa.
• What challenges do caustic ingestions pose in clinical practice?


  They pose severe challenges due to potential morbidity and mortality.
• What is the management approach for caustic ingestions?


  • Immediate airway protection
  • Stabilization
  • Symptomatic treatment
  • Supportive care
  • Endoscopic interventions
  • Surgery
• What are common clinical features of acute gastritis?


  May be asymptomatic, epigastric pain, nausea & vomiting, overt hemorrhage.
• How is chronic gastritis defined?


  • Chronic mucosal inflammatory changes
  • Leads to mucosal atrophy & intestinal metaplasia
  • Usually in absence of erosions
• What are the histological classifications of chronic gastritis?


  • Chronic superficial gastritis
  • Chronic atrophic gastritis
  • Gastric atrophy
• What are the classifications of chronic gastritis based on pathogenesis?


  • Type A or immune gastritis
  • Type B or non-immune gastritis
• What are the major etiologic associations of chronic gastritis?

  • H. Pylori chronic infection
  • Autoimmune (Pernicious Anemia)
  • Toxic (alcohol & cigarette smoking)
  • Post-surgical (antrectomy with gastroenterostomy & bile reflux)
  • Motor & mechanical issues (obstruction, bezoars, gastric atony)
  • Radiation
  • Granulomatous (Crohn’s disease)
  • Uremia
  • Graft versus host disease (GVHD)
• What are the histologic grading features of chronic superficial gastritis?


  • Inflammatory infiltrate limited to foveolar region
  • No glandular atrophy
  • Decreased cytoplasmic mucin
  • Increased nuclear and nucleolar size
  • Increased foveolar mitosis
• What are the histologic grading features of chronic atrophic gastritis?


  • Extensive inflammation
  • Glandular atrophy
  • Graded as mild, moderate, severe
  • Increased distance between glands
• What characterizes gastric atrophy in chronic gastritis?


  Thinning of mucosa in absence of inflammation.
• What is Type A (immune) gastritis characterized by?


  • Site: fundus, spares antrum
  • Antibodies against parietal cells, intrinsic factor
  • Hypo or achlorhydria
  • Increased serum gastrin and pernicious anemia
  • Associated with Hashimoto thyroiditis, Addison’s disease, type 1 diabetes
  • Risk of developing carcinoma/carcinoid tumors
• What is Type B (non-immune) gastritis characterized by?


  • Site: begins in antrum and progresses proximally to fundus
  • Associated with H. pylori, alcohol, cigarette smoke
  • Types: Hypersecretory gastritis and Environmental gastritis
• What are the endoscopic features of chronic atrophic gastritis?


  • Thin, smooth mucosa
  • Prominent submucosal vessels
• What are the microscopic features of chronic superficial gastritis?


  • Plasma cells, lymphocytes, occasional lymphoid follicles
  • +/- eosinophils and neutrophils
  • +/- reduced cytoplasmic mucin
  • Reactive epithelial changes
• What is the role of Helicobacter pylori in chronic gastritis?


  It colonizes gastric mucosa, especially in the antrum and cardia.
• How does Helicobacter pylori cause epithelial damage?


  • Disintegration and loss of apical mucin
  • Epithelial pits, erosions, and ulceration
  • Formation of lymphoid follicles
• What special stains are used to identify H. pylori?


  • Giemsa stain
  • Warthin-Starry stain
  • Immunohistochemistry (IHC)
• What are the long-term complications of Helicobacter pylori infection?


  • Chronic gastritis
  • Peptic ulcer disease
  • Gastric carcinoma
  • Gastric MALT lymphoma
• What are the regenerative changes in chronic gastritis morphology?


  • Proliferative response to epithelial injury
  • Increased mitotic figures in neck region of gastric glands
  • Enlarged epithelial cells with hyperchromatic nuclei
• What is intestinal metaplasia in chronic gastritis?


  • Partial replacement of gastric mucosa by metaplastic columnar absorptive cells and goblet cells
  • May present features of colonic epithelium
  • H. pylori absent from areas of intestinal metaplasia
• What is the significance of dysplasia in chronic gastritis?


  • Cytologic atypia may develop
  • Intestinal metaplasia may precede dysplasia
  • Severe dysplastic alterations can constitute in situ carcinoma
• What is the Sydney System of grading chronic gastritis?


  • Grading based on site: Antral, Corporal mucosa
  • Grading of: H. Pylori, Chronic inflammation, Activity, Atrophy, Intestinal metaplasia
• What is the morphology of H. pylori?


  It is a non-sporing, curvilinear gram-negative rod measuring approximately 3.5 × 0.5 μm.
• What specialized traits allow H. pylori to flourish in the stomach?


  • Motility via flagella
  • Elaboration of urease
  • Expression of bacterial adhesins
  • Expression of bacterial toxins (CagA and VacA)
• What characterizes moderate gastritis histologically?


  • Diffuse infiltrate of lymphocytes and plasma cells
  • Lymphoid aggregates in the superficial lamina propria
• How is chronic gastritis defined histologically?


  • Increased gastric intraepithelial lymphocytes (> 25 per 100 epithelial cells)
  • Lymphoplasmacytic expansion of the lamina propria
• What is intestinal metaplasia and its characteristics?


  • Affects antral & body/fundic mucosa
  • Partial replacement by metaplastic goblet cells
  • Distinct immunophenotype from intestinal metaplasia of GE junction or Barrett's esophagus
• What are the features of allergic gastritis?


  • Seen in children
  • Associated with diarrhea, vomiting, and growth failure
  • Eosinophilic infiltration
• What are the characteristics of eosinophilic gastritis?


  • Affects distal part of stomach and proximal duodenum
  • Typically affects middle-aged women
  • Associated with allergic phenomenon and peripheral eosinophilia
• What defines reactive gastropathy?


  • Characterized by foveolar hyperplasia
  • Loss of mucin
  • Glandular regenerative changes
  • Absence of neutrophils
• What are the clinical features of chronic gastritis?


  • Nausea
  • Vomiting
  • Upper abdominal discomfort
  • Burning pain
  • Hypochlorhydria due to parietal cell loss
  • Pernicious anemia in autoimmune gastritis