path of stomach and small intestine

Question 1

List the general features and causes of acute and stress-related gastritis.

Answer 1

Features include epigatric pain, early satiety, n/v, melena, hematemesis
H. pylori and NSAIDS, chemical injury, alcohol and tobacco
Stress-related gastritis is due to vasoconstriction/ischemia. Occurs in 75% of critically ill patients:
Stress ulcers (trauma, shock)
Burns (Curling ulcers)
Intracranial disease (Cushing ulcers)
Congenital hypertrophic pyloric stenosis

Question 2

Understand the pathophysiology, epidemiology, and common sequelae of Helicobacter infection.

Answer 2

Most common cause of chronic gastritis.
Gram-negative bacillus adapted to gastric environment
Flagella to maneuver through gastric mucus
Adhesion molecules bind to gastric foveolar cells
Acid resistance through abundant urease
Elaboration of toxins cause tissue damage
Minimization and evasion of immune response
Oral-oral, fecal-oral, and environmental spread
Associated with poverty, household crowding, and rural areas

Question 3

Understand the pathophysiology and common sequelae of autoimmune gastritis.

Answer 3

Another cause of chronic gastritis.
Corpus restricted chronic atrophic gastritis
Anti-parietal cell and anti-intrinsic factor antibodies
+/- pernicious anemia
Scandinavian and northern European descent

Question 4

Discuss the complications of peptic ulcer disease.

Answer 4

Complications include bleeding, perforation, obstruction, cancer

Question 5

Compare and contrast the appearance of the common types of gastric polyps, their associated conditions, and their relationship to gastric cancer.

Answer 5

Inflammatory/
hyperplastic polyp
++++
Rare progression to cancer; associated with Helicobacter and other chronic gastritides

Fundic gland polyp
+++
Very rare progression to cancer (in FAP patients); FAP associated and sporadic (usually PPI associated)

Adenoma
++
Common progression to cancer; increased incidence in FAP, Helicobacter gastritis, and other chronic gastritides

Juvenile polyp
+
Hamartomatous polyp (discussed in neoplastic intestinal disease lecture)

Peutz-Jeghers polyp
+
Hamartomatous polyp (discussed in neoplastic intestinal disease section)

Question 6

Be acquainted with the risk factors, epidemiology, associations, and natural history of gastric adenocarcinoma.

Answer 6

Accounts for 90% of all malignant gastric tumors
Second most common fatal malignancy in the world
But not in USA (accounts for only 2.5% of cancer deaths)
High incidence in Japan, Chile, and Eastern Europe
Risk factors: environment (diet) and Helicobacter

Symptoms
Early: dyspepsia, dysphagia, and nausea
Late: weight loss, anorexia, early satiety, anemia
High mortality unless disease detected early
Overall 5-year survival is 30% (90% for early gastric cancer)
Less than 20% of gastric cancers in USA detected early

Wnt signalling pathway activation
Common in intestinal type cancers
Can occur with loss of APC (as in FAP)

Question 7

Describe the appearance, natural history, and molecular features of gastrointestinal stromal tumors. GIST

Answer 7

Mesenchymal neoplasm derived from interstitial cells of Cajal (pacemaker cells controlling peristalsis)
mutation in the c-kit oncogene- Used as diagnostic aid on tissue
Targeted therapy with tyrosine kinase inhibitor imatinib
Variable clinical course – indolent to malignant
Risk assessment: location, mitotic rate, and size

Question 8

Malt lymphoma

Answer 8

Key Point: Many gastric lymphomas can be cured with antibiotics because they are related to H pylori