Pathology of the Stomach Flashcards Preview

DEMS: Unit 1 > Pathology of the Stomach > Flashcards

Flashcards in Pathology of the Stomach Deck (22):
1

Anatomic landmarks of stomach

  • cardia
  • fundus
  • body
  • antrum
  • pylorus

2

Characteristics of gastric mucosal barrier

  • surface mucus secretion
  • bicarbonate secretion into mucus
  • epithelium = performs barrier fxn
    • good regenerative capacity
    • elaboration of prostaglandins

3

Adult vs. Juvenile pyloric stenosis

  • infantile (congenital)
    • hyperplasia of pyloric muscularis propria ==> obstruction of gastric outflow
    • presents 2nd-3rd week of life (M>>F)
      • regurg + projectile vomiting
      • firm ovoid abdominal mass
  • adult (aquired)
    • consequence of antral gastritis or peptic ulcers close to pylorus

4

Gastritis vs. Gastropathy

•Gastritis = Mucosal inflammatory process
•Gastropathy = Mucosal changes without much inflammation.
 

5

Causes of acute gastritis

  • **H. pylori
  • ** NSAIDs, drugs
  • stress-related ulcers
  • alcohol, diet
  • chemical ingestion

6

Features?

  • dx: small gastric ulceration (acute gastritis)
  • features
    • acute inflammation (PMNs)
    • erosion of epithelium

7

Most common causes of chronic gastritis

  1) ***Helicobacter pylori*** - antrum

  2) Autoimmune gastritis (less than 10% of cases of chronic gastritis) - body

8

Histologic features of H. pylori chronic gastritis

  • H. pylori stain
  • usually acute on chronic gastritic changes
  • lymphs and plasma cells @ lamina propria
  • lymphoid aggregate w/germinal center

9

Peptic Ucler Disease definition

  • Disease characterized by peptic ulcers 
  • peptic ulcer = distinct breach in the mucosal lining of the esophagus (esophageal ulcer), stomach (gastric ulcer) or the first part of the small intestine (duodenal ulcer)
  • ulcers result from caustic effects of acid and pepsin in the lumen

10

Risk factors for development of PUD

  • H.pylori infection → compromise mucosal defense → gastric hyperacidity → mucosal damage and ulceration
  • NSAID use → direct chemical irritation + suppression of prostaglandin synthesis
  • Cigarettes → impairs mucosal blood flow and healing
     

11

Diseases associated w/H. pylori infection

    1.)   Acute and chronic gastritis

    2.)   Gastric and duodenal ulcers (PUD)

    3.)   Gastric adenocarcinoma

    4.)   MALT Lymphoma (mucosa associated lymphoid tissue)

12

Characteristics of autoimmune chronic gastritis

  • <10% of chronic gastritis
  • SPARES antrum; mostly occurs @ BODY
  • ==> destruction of parietal cells
    • decreased acid + elevated gastrin
    • pernicious anemia (decreased IF)

13

Most common types of stomach polyps

  1. hyperplastic polyp
    1. antrum > body
    2. H. pylori associated
  2. polypoid gastritis
    1. antrum > body
    2. H. pylori associated
  3. adenoma
    1. antrum > body
    2. solitary, malignant precursor

14

Characteristics of hyperplastic polyps

  • Inflammatory polyp, arise in association with chronic gastritis
  • Exaggerated mucosal response to injury and inflammation
  • cellular origin: Foveolar epithelium and lamina propria
     

15

Characteristics of gastric adenomas

  • Adenomas exhibit dysplasia and are precursors to adenocarcinoma (malignancy)
  • Arise in a background of chronic gastritis with atrophy and intestinal metaplasia
  • cellular origin: dysplasia of lining epithelial cells
  • Evolution of an Adenoma:
    • Chronic gastritis  ==> intestinal metaplasia ==>  low-grade dysplasia/”adenoma” ==> high-grade dysplasia ==> invasive adenocarcinoma

16

Common types of gastric tumors

  • Adenocarcinoma
  • Gastrointestinal Stromal Tumors (GIST)
  • Neuroendocrine tumors (carcinoid)
  • Lymphoma (MALT)
  • Metastatic tumors
    • Melanoma
    • Breast
       

17

Characteristics of gastric adenocarcinoma

  • Epithelial tumor derived from malignant  transformation of the gastric epithelium (precursor lesion = adenoma)
  • Subtypes
    • Intestinal type – tends to form masses
    • Diffuse type – diffusely infiltrative 

18

Risk factors: Intestinal Adenocarcinoma vs. Diffuse Adenocarcinoma

  • Both: Chronic gastritis, H.pylori  infection
  • Intestinal type: 
    • Tobacco
    • diet (smoked foods, salted fish/meat, pickled vegetables)
    • inherited cancer syndromes
  • Diffuse type:
    • Mutations in CDH1 (Hereditary Diffuse Gastric Cancer)
       

19

Gross findings: Intestinal Adenocarcinoma vs. Diffuse-type Adenocarcinoma

  • Intestinal type:  Ulcer with heaped-up borders
  • Diffuse type: “Linitis plastica” thickened wall with loss of rugal folds, leather bottle 

20

Histologic features: Intestinal vs. Diffuse-type adenocarcinoma

  • intestinal = glandular, fibrosis
  • diffuse type = signet ring cells

21

Characteristics of GI Stromal Tumors (GIST)

  • clinical
    • older pt/s 
    • weight loss, anemia, dyspepsia
  • pathogenesis
    • Stromal tumor derived from the Interstitial Cells of Cajal
      • ICC = pacemaker cells for gut peristalsis @ muscularis propria
    • 80% are due to an activating mutation in the gene encoding the tyrosine kinase CKIT
    • KIT negative GIST: Majority are gastric/extraintestinal: PDGFRA mutated
       

22