Stomach Flashcards
Name the anatomic regions of the stomach
- Cardia: most proximal part of stomach, extending a few mm from anatomic GEJ
- Fundus: dome-like portion of proximal stomach; functionally body
3. Body: rest of ~proximal 2/3 - Antrum/pylorus: ~distal 1/3; roughly begins at incisura angularis
Which types of glands are found in the cardia, corpus, and antrum?
- cardia (mucous cells, loosely arranged)
- corpus (oxyntic; parietal, chief cell, and ECL-cell containing)
- antral (mucous cells, G cells)
Parietal cells secrete what?
- produce H+ under the control of vagal stimulation (acetylcholine), histamine (ECL cells), and gastrin (G cells)
- Intrinsic factor
Chief cells secrete what?
pepsinogen
ECL cells secrete what?
histamine
T/F- gastrin promotes H+ production and H+ feedback inhibits gastrin
true
If you remove feedback inhibition (e.g. PPI) on parietal cells, what will happen?
G cell hyperplasia leads to hypergastrinemia
Review gastroduodenal alarm features (increase pretest probability of malignancy)
Unintended weight loss Persistent vomiting Progressive dysphagia Odynophagia Unexplained anemia Hematemesis Palpable mass/adenopathy Family history of upper GI cancer Previous gastric surgery Jaundice
Review indications for gastroscopy
Upper tract symptoms unresponsive to empiric tx
Upper tract symptoms with alarm features
Active/recent upper GI bleeding
Chronic blood loss/iron deficiency anemia (with negative colonoscopy)
Confirm eradication of H. pylori infection in patients with ulcer, persistent symptoms, MALT lymphoma, early gastric cancer
Acute caustic ingestion
Follow up of lesion seen on imaging
Surveillance of premalignant condition
Therapeutic maneuvers
An infant presents with projectile, non-bilious vomiting in the first few weeks of life and an olive shaped abdominal mass if found on physical exam. What is it?
Hypertrophic pyloric stenosis
An infant presents with severe respiratory distress, pulmonary hypertension and hypoplasia are noted. What is it?
Congenital diaphragmatic hernia (most through the foramen of Bochdalek-back and to the left)
What is heterotopia?
presence of normal tissue in an abnormal anatomic location
Name two important gastropathies implicated in GI bleeding
- portal hypertensive gastropathy (PHG)
- Gastric antral vascular ectasia (GAVE)
A patient with PORTAL HYPERTENSION comes in and has an endoscopy done. MOSAIC or SNAKE SKIN LIKE patterns are seen in the BODY of the stomach. What do they have and how is it treated
- portal hypertensive gastropathy (PHG)
- reduce portal pressure with B-blockers
A patient with SEVERE LIVER DISEASE, CONNECTIVE TISSUE DISEASE, and chronic RENAL disease who just had a BONE MARROW TRANSPLANT undergoes endoscopy and RED STRIPES RADIATING FROM PYLORUS (WATERMELON STOMACH) is seen. Microscopic exam reveals dilated mucosal micro vessels and FIBRIN THROMBI. What do they have and how is it treated?
Gastric antral vascular ectasia (GAVE)
Treat with thermal ablation
What is the difference between gastritis and gastropathy?
Gastritis – gastric mucosal injury with conspicuous inflammatory component (Acute, Helicobacter, Autoimmune)
Gastropathy – inflammation-poor gastric mucosal injury
Reactive (chemical) (NSAID’s, Bile reflux) or Vascular
Name 5 complications of gastritis/gastropathy
- Peptic ulcer disease (Helicobacter, NSAID’s)
- Intestinal metaplasia, dysplasia carcinoma (Helicobacter, autoimmune)
- MALT lymphoma(Helicobacter)
- Neuroendocrine (carcinoid) tumor (autoimmune)
- B12 deficiency (autoimmune)
T/F- H. pylori is found in nearly 100 percent of gastric ulcers?
False, nearly all duodenal tumors and most gastric ulcers
What is the dominant symptom of H. pylori gastritis?
dyspepsia (although may also be asymptomatic)
What does triple therapy consist of?
PPI, amoxicillin, clarithromycin
T/F- duodenal ulcer, gastric ulcer, gastric carcinoma, and MALT lymphoma are risks associated with H. pylori gastritis
true
Describe the pathophysiology of duodenal peptic ulcers with respect to H. pylori infection
In antral-predominant gastritis, H. pylori results in decreased somatostatin (normally inhibits gastrin), increased gastrin, and increased basal and stimulated acid secretion (especially in patients predisposed to ulcer)
T/F- patients with a corpus predominant pattern of helicobacter gastritis are at an increased risk of developing GASTRIC CANCER compared to antral predominant pattern
true
CD20 stains ___
CD3 stains ___
CD20: B cells
CD3: T cells
Is MALT lymphoma associated with H. pylori?
yes
H. pylori detected in 90% of cases, and many cases will spontaneously resolve with Helicobacter eradication. buzzword is LYMPHOEPITHELIAL LESION
Autoimmune (atrophic) gastritis is most common in northern europeans. Autoantibodies are produced and attack what structures?
parietal cells/intrinsic factor
Autoimmune gastritis can cause what complications?
B12 deficiency, pernicious anemia (PA), subacute combined degeneration; carcinoid tumors (10% of pt’s with PA); gastric cancer (1-3%; RR 3-18)
In atrophic gastritis, the atrophy manifests as loss of what structure?
rugal folds
Name 3 clinical reasons for a carcinoid tumor
- Autoimmune gastritis
- Zollinger-Ellison syndrome (gastrinoma)
- Sporadic
1 & 2 are driven by hypergastrinemia
Reactive (chemical) gastropathy is the 2nd most common dx made on gastric biopsies. What are 2 main causes?
- NSAIDs
2. Bile Reflux
What are 3 key features of fundic gland polyps?
- Benign, non-progressing neoplasms
- Linked to PPI use
- Fundic gland polyposis in FAP
Hyperplastic polyps are the most common gastric polyp. What is their significance?
Key significance is a marker for underlying gastric pathology (inflammatory polyp, exaggerated regeneration in a field of inflammatory mucosal pathology such as gastritis or gastropathy)
A xanthoma means yellow tumor (collection of lipid-laden macrophages in lamina propria). What is the significance of this in the stomach?
Only significance is as maker of past or ongoing injury (similar to hyper plastic polyp)
Review key facts about gastric adenoma
- Polyps composed of dysplastic epithelium
- Can occur “sporadically” (as in colon) but generally arise in inflammatory mucosal pathology
- Can progress to gastric cancer (although most cancers arise in “flat” dysplasia)
- Should be removed; indication for surveillance
What mutation is present in 80% of GI stromal tumors?
KIT activating mutations leading to constitutive tyrosine kinase activity (treat with imatinib mesylate)
Describe linitis plastica
- Diffuse; dyscohesive; signet-ring-cells
- Results from CDH1 (e-cadherin) mutation/loss of function, including hereditary examples
Describe polypoid cancer
-Intestinal; tubular; gland-forming, -Develop via gastritis to intestinal metaplasia to dysplasia to carcinoma sequence)
T/F- HER2 oncoprotein is overexpressed in 20% of gastric and 30% of GEJ carcinomas and predicts response to trastuzumab (herceptin)
true
