Nelson: Gastric Pathology Flashcards
(46 cards)
What are the normal damaging forces of the gastric mucosa?
Gastric acidity
Peptic enzymes
What are the main mechanisms of gastric mucosal injury?
- H. pylori infection
- NSAIDS
- Aspirin
- Alcohol
- Cigarettes
- Gastric hyperacidity
- Duodenal gastric reflux
What are the main defenses of the gastric mucosa?
- surface mucus secretion
- bicarbonate secretion into the mucus
- mucus blood flow
- apical surface membrane transport
- epithelial regenerative capacity
- increased PGs
What is the difference between a mucosal erosion and a mucosal ulcer?
A mucosal erosion is the loss and necrosis of surface epithelium that is CONFINED to the LP.
An acute ulceration is a necrotizing process that often extends beyond the mucosa into the submucosa and maybe even the muscle wall.
What are the main causes of acute gastric ulceration?
- Acute infection w/ H. Pylori
- First time use of large dose of NSAIDS or ASPIRIN (COX inhibitor)
- ingestion of large doses of alcohol
- Shock, trauma, sepsis, uremia, burns and intracranial disease
What is the MC pathological finding in H. pylori gastritis?
Active chronic gastritis beginning in the antrum and progressing to the body.
Histologically you would see lymphocytes in the active germinal center and a bunch of neutrophils indicating acute inflammation.
What complications are associated w/ an h. pylori infection?
MALT lymphoma
Gastric adenocarcinoima
What are hallmarks of chronic gastritis?
Evidence of CHRONIC inflammation= lymphocytes + plasma cells + reactive gastropaty
How do you acquire H. helmannji gastritis?
It’s reservoir is cats, dogs, pigs and nonhuman primates
Which H. pylori diagnostic tests are indicative of an active infection?
H & E, blue stain and immunohistochemical stain of biopsy specimen.
H. pylori stool antigen, urea breath test or rapid urease test on tissue biopsy
Describe the pathogenesis of autoimmune gastritis.
An autoimmune response causes CD4 T cells to target and destroy parietal cells (chief cells are also lost–collateral damage).
Abs to parietal cells and IF are also produced as part of the immune response. They ARENT pathogenic but can be used as a diagnostic test.
What are the key findings of autoimmune gastritis?
- Fewer parieatl cells> Decreased acid secretion (achlorhydria
- Hypergastrinemia and hyperplasia of G cells> compensatory endocrine hyperplasia in the body of the stomach
- B12 def d/t loss of IF
- Inflammatory damage in teh body and fundus sparing the antrum and cardia.
What are signs of B12 def?
Pernicious anemia w/ increased MCV
Megaloblastic anemia
Atrophic glossitis
malabsorptive diarrhea
Peripheral neuropathy
What are common causes of chronic reactie gastropathy?
Chemical mucosal injury associated w/ NSAIDS, aspirin, bile reflux and alcohol
What are two common causes of peptic ulcer disease?
H. Pylori
Chronic use of NSAIDs
What are the three complications of peptic ulcer disease?
- Bleeding (clinical hemorrhage and iron def)
- Perforation
- Obstruction (ulcer located in pyloric channel secondary to edema and fibrosis)
What are the key pathologic and clinical features of eosinophilic gastritis?
Eosinophilic rich inflammation–> peripheral (blood) eosinophilia and elevated IgE.
Absence of known cause but thought to be secondary to food allergy.
Often involves MULTIPLE GI sites.
Pt presents w/ mass, ulcer or pyloric obstruction.
What are the key pathologic and clinical features of granulomatous gastritis?
Gastritis w/ granulomatous inflammation.
Usually d/t an underlying disorder:
Crohn’s- most common cause in US
Sarcoidosis
Mycobacterial, fungal and parasitic infections (rare)
Foreign body rxn
Association with gastric adenocarcinoma and non-MALT lymphomas
What are the key pathologic and clinical features of lymphocytic gastritis?
Intraepithelial lymphocytic inflammation (CD8 T cells)
40% of cases are seen in pt/s w celiac so it suggests an immune pathogenesis.
Also seen w/ menetrier’s, h. pylori and lymphocytic/collagenous colitis.
What is Menetrier’s disease? What does this mean clinically? What is Menetrier’s disease associated with? Which cancer can it predispose you to?
Excess secretion of TGF-α leads to diffuse hyperplasia of the body and fundus of stomach.
Pt’s lose protein with diarrhea (enteropathy), hypoprotenemia weight loss and peripheral edema.
Some cases associated with infection (CMV in children).
Increased risk for gastric adenocarcinoma.
What causes ZE syndorme?
Gastrin secreting tumors in the pancreas and small bowel leads to elevated levels of gastrin that increase the number of parietal cells and in turn acid production.
It also leads to hyperplasia of mucus neck cells w/ increased mucin production.
Who does ZE syndrome predispose you to cancer?
Stomach endocrine cell proliferation can lead to gastric CARCINOID tumors.
How do pt’s with ZE syndrome present?
PUD or chronic diarrhea
How do you treat ZE syndrome?
Remove tumor and give PPI
