Stomach Pathology Overview

Stomach Pathology

• Stomach diseases encompass congenital abnormalities, gastritis, hypertrophic gastropathy, peptic ulcers, gastric polyps (non-neoplastic), and stomach tumors.

Congenital Abnormalities

• Pyloric stenosis: Characterized by abnormal thickening of the pylorus muscles, leading to pyloric valve stenosis.
• This condition primarily affects male infants more than females (4:1 ratio).
• Clinical features: Persistent projectile vomiting (typically in the second week of life), and a palpable epigastric mass (the thickened pylorus).

Gastritis

• Acute gastritis: Transient inflammation of the stomach's mucosal lining.
• Common causes: Chronic use of NSAIDs (especially aspirin), heavy smoking, excessive alcohol consumption.
• Less common causes: Severe stress (e.g., burns, surgery), uremia, ischemia, shock, systemic infections, radiation, certain chemotherapy drugs, ingestion of acids/alkalis.
• Gross appearance: Mucosal edema (swelling) and hyperemia (redness). Potential ulceration and hemorrhage.
• Microscopic: Infiltration of the epithelial layer by neutrophils (a type of white blood cell).
• Clinical manifestations: Epigastric pain and hematemesis (vomiting blood).

Chronic Gastritis (Type A - Fundic)

• Autoimmune atrophic gastritis: Chronic inflammation of the fundus and body of the stomach.
• Autoantibodies to parietal cells and/or intrinsic factor are detectable in the patient's serum.
• Effects: Decreased acid secretion (achlorhydria) and increased serum gastrin (G-cell hyperplasia).
• Potential complication: Pernicious anemia (megaloblastic anemia) due to intrinsic factor deficiency, resulting in B12 malabsorption.
• Gross appearance: Loss of rugal folds (normal stomach folds) in the fundus and body.
• Microscopic: Partial mucosal atrophy (thinning), loss of glands and parietal cells, chronic inflammation (lymphocytes & plasma cells), and potential intestinal metaplasia with dysplasia in some cases.
• Risk of gastric carcinoma.

Chronic Gastritis (Type B - Antral)

• H. Pylori gastritis: A common disease caused by infection with Helicobacter pylori.
• Microscopic: Helicobacter pylori organisms are visible within the stomach lining (intracellular and extracellular).
• Chronic inflammation of the gastric mucosa and lymphocyte follicles may be observed.

Hypertrophic Gastropathy

• Uncommon disorders: Characterized by enlargement of the gastric rugal folds.

• Two types: A) Ménétrier disease and B) Gastric gland hyperplasia (Zollinger-Ellison syndrome).

• Ménétrier disease: Classic triad of gastrointestinal symptoms (epigastric pain, anorexia, vomiting), peripheral edema, and giant gastric folds. Characterized by mucous cell hyperplasia and fundic gland atrophy with excess mucus secretion. Decreased acid production is also seen.

• Zollinger-Ellison syndrome: Excessive gastrin secretion from a gastrinoma (tumor in the pancreas) that stimulates gastric gland hyperplasia and excessive acid secretion. Results in excess acid, leading to multiple ulcers. Common symptom is abdominal pain, nausea, vomiting, bleeding, weight loss and diarrhea.

Chronic Peptic Ulcers

• Open sores: Found on the inner lining of the stomach and/or duodenum.
• Common cause: Usually solitary in nature and caused by exposure to gastric secretions.
• Sites: Primarily duodenal (80%) and gastric (20%).
• Pathogensis: Imbalance between gastro-duodenal mucosal defense mechanisms (mucus and bicarbonate secretion, mucosal blood flow, regeneration) and damaging forces (excess gastric acid and pepsin, H. pylori infection, NSAIDs [aspirin], smoking, excessive alcohol.).
• Gross appearance: Round or oval ulcers. Clean bases. Radiating mucosal folds, smaller in duodenum than stomach.
• Microscopic: Necrotic debris at base of ulcers, zone of active inflammation around ulcers, and fibrous collagen scar tissue.
• Complications: Hemorrhage (hematemesis and melena—black, tarry stools). Perforation or penetration of an ulcer into an adjacent organ (e.g., liver). Healing results in pyloric stenosis or hourglass deformity of stomach. Potential for malignant change (carcinoma, occurring in roughly 1% of gastric ulcers, but less common in duodenal ulcers).

Duodenal Peptic Ulcer

• More common than gastric ulcers (4:1 ratio).
• Commonly associated with: H. pylori infection (~100%). Increased gastric acid secretion. Increased rate of gastric emptying.
• Site: Anterior wall of the duodenum's first portion.

Gastric Peptic Ulcer

• Often associated with: H. pylori infection in 75% of cases.
• Site: Located on the lesser curvature near the pyloric antrum.
• Clinical features: Burning epigastric pain that worsens with eating.

Gastric Polyp

• Hyperplastic or inflammatory in nature (90%).
• Common location: In patients with chronic gastritis.
• No malignant potential (usually).
• Gross appearance: Commonly multiple, smooth surface, sessile or pedunculated.
• Microscopic: Tubules and cysts lined by columnar cells, interspersed with inflammatory stroma.

Gastric Tumors (Benign)

• Adenomas (adenomatous polyps): 90% of benign gastric tumors. Polypoid masses, single or multiple, sessile or pedunculated. Potential for malignancy.
• Other benign tumors: Leiomyoma, lipoma, hemangioma.

Gastric Carcinoma (Pathogenesis - Risk Factors)

• Dietary factors: Preservatives (nitrates), lack of fresh fruits/vegetables.
• Infections: H. pylori infection with chronic gastritis.
• Autoimmune gastritis.
• Cigarette smoking.
• Gastric adenoma.

Gastric Carcinoma (Gross Appearance)

• Sites: Mostly found in the lesser curvature of the gastric antrum.
• Morphological types: Exophytic/polypoid (projecting intraluminal masses), excavated/ulcerative (heaped-up margins, necrotic floor, indurated base), or flat/infiltrating (invades stomach wall, resulting in a contracted stomach—linitis plastica).

Gastric Carcinoma (Microscopic Appearance)

• Adenocarcinoma: Well-differentiated (intestinal type) or mucinous (pools of mucin).
• Signet-ring cell carcinoma.

Gastric Carcinoma (Clinical Features)

• Asymptomatic: In 90% of cases initially.
• Weight loss, epigastric pain/fullness, occult bleeding (in the stool).

Gastric Carcinoma (Prognosis)

• Early resected cases: 5-year survival rate of 90% (good prognosis).
• Advanced cases: 5-year survival rate of 10% (poor prognosis).

Other Less Common Malignant Gastric Tumors

• Lymphoma (MALT lymphoma): Less than 15% of gastric tumors.
• Leiomyosarcoma (1-3%).
• Carcinoid tumor.
• Gastric malignant schwannoma.

Peptic Ulcer vs. Malignant Ulcer (Comparison)

• Age: Peptic ulcer: Younger (30-40). Malignant ulcer: Older (50-70).
• Gastric acidity: Peptic: Usually increased. Malignant: Normal/absent.
• Ulcer shape: Peptic: Sloping edge, fibrotic base. Malignant: Heaped/up margins, necrotic floor, indurated base, muscle layer infiltrated.

Explore the various diseases and conditions affecting the stomach, including congenital abnormalities, acute gastritis, and more. This quiz covers key features, causes, and symptoms related to stomach pathology. Test your knowledge on the clinical aspects of stomach diseases.