2. Acute Gastritis:
• Gastritis: inflammation of the gastric mucosa.
• Diagnosis mostly histological.
• Acute Gastritis:acute mucosal inflammatory
process usually of a transient nature.
• neutrophilic infiltration
• Etiology:
Heavy use of NSAID’s, particularly aspirin
Excessive alcohol consumption&Heavy smoking
3. Treatment with cancer chemotherapeutic drugs Gastric
irradiation or freezing
Systemic bacterial or viral infections
Severe stress& Mechanical trauma
Ischemia, shock & uremia
Distal gastrectomy.
• Pathogenesis:
increased acid secretion with back-diffusion,
decreased production of bicarbonate buffer,
reduced blood flow,
disruption of the adherent mucus layer,
direct damage to the epithelium.
4. • Morphology:
the gastric mucosa demonstrates
edema, neutrophilic infiltrates, mucosal
erosions, and, if severe, ulceration &
hemorrhage.
FIGURE 17–13 B.Low-power microscopic view of focal mucosal disruption with hemorrhage;
the adjacent mucosa is normal.
5. Chronic Gastritis:
• Chronic gastritis is defined as the presence of
chronic mucosal inflammatory changes leading
eventually to mucosal atrophy and intestinal
metaplasia, usually in the absence of erosions
• Etiology:
Chronic infection by H. pylori
Immunologic,(in association with pernicious
anemia)
6. Toxic,(alcohol &cigarette smoking)
Postsurgical,(esp following antrectomy with
gastroenterostomy)
Motor and mechanical,(obstruction, bezoars&
gastric atony)
Radiation
Granulomatous conditions (e.g., Crohn disease)
Misc.—amyloidosis, graft-versus-host disease
,uremia.
• Pathogenesis:
7. oChronic atrophic gastritis caused by H.pylori:
• (1) Gram-negative, curved rod
• (2) Produces urease, proteases, cytotoxins
(a) Urease converts amino groups in proteins to
ammonia
(b) Secretion products produce chronic gastritis
and PUD,
• (3) Colonizes mucus layer lining
oAutoimmune atrophic gastritis:
• Autoantibodies to parietal cells (H/K ATPase
proton pump) and intrinsic factor
8. • Morphology:
• Chronic inflammatory infiltrate(lymphocytes
&/or plasma cells) in the lamina propria
• Intestinal metaplasia(Precursor lesion for
adenocarcinoma)
• Intestinal atrophy
• Epithelial dysplasia
• FIGURE 17–14 Chronic gastritis, showing partial replacement of the gastric mucosal epithelium by
intestinal metaplasia (upper left) and inflammation of the lamina propria (right) containing
lymphocytes and plasma cells.
