Gastric Path Nelson Flashcards
Describe the normal damaging forces on gastric mucosa
Gastric Acidity
Peptic Enzymes
Describe the defensive forces of the gastric mucosa
- Surface mucus secretion
- Bicarb secreted in mucus
- Mucosal Blood flow
- Apical surface membrane transport
- Epithelial regenerative capacity
- Elaboration of prostaglandins
Main general mechanisms of mucosal injury
-H. pylori infection NSAIDS Aspirin Cigarettes Alcohol Gastric Hyperacidity Duodenal-gastric reflux
Leads to: Ischemia Shock Delayed gastric emptying Host factors
What are the layers of an ulcer?
Necrosis
Inflammation
Granulation Tissue
Fibrotic scar (only present in chronic lesions)
What are some causes of acute gastritis?
- Acute infection H. pylori
- First time, large dose NSAIDS
- Alcohol
- Acute stress ulcers from shock trauma, sepsis, uremia, burns, etc.
Most common pathologic finding in H. pylori gastritis
Active chronic gastritis beginning in Antrum and progressing to fundus
Complications of H. pylori infection
MALT lymphoma
Gastric adenocarcinoma
How does one acquire H helmanni gastritis?
Reservoir in cats, dogs, pigs, and non human primates
Dogs licking your face????? WHAT????
Which H. pylori diagnostic test indicate active infection?
- double check this one
- Stool antigen
- Urea breath test
- Rapid urease test on fresh tissue biopsy
Pathogenesis of autoimmune gastritis
CD4+ T-cell mediated destruction of parietal cells (and chief cells).
Key findings and complications of autoimmune gastritis
- decreased gastric acid secretion
- Compensatory hypergastrinemia, hyperplasia of G cells and ECL cells
- B12 deficiency (loss of intrinsic factor)
- Reduced pepsinogen
- Mucosal damage and atrophy
Common causes of chronic reactive gastrophy
-chemical mucosal injury NSAIDS Aspirin Bile reflux Alcohol
Two common causes of peptic ulcer disease
- H. pylori infection
- Chronic use of NSAIDS
Three complications of peptic ulcer disease
- Bleeding
- Perforation
- Obstruction (especially when the ulcer is located in the pyloric channel)
Key features of eosinophilic gastritis
Eosinophil rich inflammation in the absence of a known cause for eosinophilia
Rare
Key features of granulomatous gastritis
Graulomatous inflammation
Usually secondary to underlying disorder: Crohn’s, Sarcoid, mycobacterial or fungal infections
Key features of lymphocytic gastritis, which T-cells?
Gastritis with lymphocytic inflammation = CD8+ T cells
Menetrier’s Disease
Rare
Excessive secretion of transforming growth factor alpha (TGF-alpha)
Results in diffuse hyperplasia of the foveolar epithelium
Zollinger-Ellison Syndrome
Caused by gastrin secreting tumors
Elevated gastrin results in increased parietal cells = increased gastric acid production
Hyperplastic Polyp
Most common
Exaggerated mucosal response to tissue injury/inflammation
Associated with chronic gastritis
Cystic fundic gland polyp
Most associate with PPIs secondary to increased gastric secretion in response to decreased gastric acid
Gastric Adenoma
Neoplastic polyp morphologically similar to other adenomas found in GI tract
Inflammatory fibroid polyp
- mesenchymal polypoid proliferation
- mixture of stromal spindles cells, blood vessels, inflammatory cells
- common in middle aged females
Clinical presentation and treatment of congenital hypertrophic pyloric stenosis
Stenosis due to hyperplasia of pyloric muscularis propria
more common in males
presents 3rd ish week of life: regurgitation and projectile vomiting
Surgical myotomy is curative
Risk factors for gastric adenocarcinoma
- Chronic gastritis
- Dietary carcinogens
- Menetrier’s Disease
- Diets w/out antioxidants
- Familial Adenomatosis Polyposis
Two morphological patters of gastric adenocarcinoma
Intestinal type = invasive mass or ulcer, glandular differentiation
Diffuse type= thickening of gastric wall, signet-ring cells
Most common location of GIST tumor
Stomach
What types of cells do GIST tumors differentiate to?
interstitial cells of Cajal, specialized cells involved in gut peristalsis
What is the key genetic defect of GIST tumor?
oncogenic, gain-of-function mutations of the gene encoding receptor tyrosine kinase KIT.
What is the rational for the use of Gleever in GIST?
Gleever = tyrosine kinase inhibitor
To treat GIST (gain of function mutations for tyrosine kinase KIT)
Most common risk factor for gastric MALT lymphoma
H. pylori infection
First line therapy for gastric MALT lymphoma
Eradication of H. pylori infection with antibiotics
Pathogenesis of carcinoid syndrome?
?
Diagnostic test for carcinoid syndrome
?
Define peritonitis, common causes?
Defined as inflammation of the thin, mesothelial covered layer of tissue that lines the abdominal cavity (peritoneum)
Many causes: perforation of viscus, diverticulitis, leakage of bile contents causing irritation, foreign material, localized hemorrhage
Define ascites
Accumulation of excess fluid in peritoneal cavity
Most common cause of ascites?
portal hypertension associated with cirrhosis
Most significant complication of ascites?
spontaneous bacterial peritonitis
Rational for laboratory test on ascitic fluid?
cell count- determine if infection
Gram stain/culture - duh
Albumin/total protein- determine if exudate or tansudate
Fluid cytology if malignancy is suspected
Which two metastatic tumors are most common cause of malignant ascites?
?
Define idiopathic retroperitoneal fibrosis
A dense fibrosing process that can result in renal failure due to ureteral obstruction
