2- Stomach
Chronic Gastritis
Etiology:
The primary cause of chronic gastritis is infection with Helicobacter pylori.
Another significant cause is autoimmune gastritis.
Less prevalent causes include radiation injury and chronic bile reflux.
Symptoms:
Symptoms associated with chronic gastritis tend to be less severe than acute gastritis but are more persistent.
Morphology
Organism Localization:
The H. pylori organism is primarily found in the superficial mucus that covers the epithelial cells in the gastric mucosa.
Inflammatory Reaction:
There is typically a notable inflammatory response, both acute and chronic, that includes lymphoid aggregates, some of which exhibit germinal centers.
Intestinal Metaplasia:
Over time, intestinal metaplasia can develop, evidenced by the presence of goblet cells, which is linked to an increased risk of gastric adenocarcinoma.
Pathogenesis of Peptic Ulcer Disease (PUD)
Gastric Hyperacidity:
Hyperacidity is crucial to the development of PUD, which may stem from:
H. pylori infection
Parietal cell hyperplasia
Tumors such as Zollinger-Ellison syndrome, characterized by excessive gastrin release leading to heightened acid production.
Disruption of Mucosal Protection:
Factors disrupting mucosal defenses include:
Chronic NSAID use
Cigarette smoking
High-dose corticosteroids, which inhibit prostaglandin synthesis.
Conditions such as hypercalcemia can also induce PUD by stimulating gastrin production, thus increasing acid secretion.
Chronic Gastric Ulcer (Microscopic Features)
Cellular Features:
Fibrin Presence: Indicates ongoing inflammation.
Inflammation: Persistent inflammation characterizes chronic ulcers.
Granulation Tissue: Forms as part of the healing process.
Fibrosis: May develop over time, resulting in complications.
Complications of Chronic Gastric Ulcer
Hemorrhage:
Can lead to hematemesis (vomiting blood) and melena (black stool).
Chronic blood loss may result in anemia.
Perforation:
Can cause the passage of food, gastric juice, and bacteria into the peritoneal cavity, leading to peritonitis.
Fibrosis:
May result in pyloric obstruction due to scar tissue formation.
Malignant Changes:
Rare, occurring in less than 1% of cases.