Pathology- stomach Flashcards
where does the pyloric channel end
where the duodenum begins
what can cause acute gastritis
irritant chemical injury, severe burns, shock, severe trauma, head injury
what can cause chronic gastritis
ABC;
- autoimmune
- bacterial- H pylori
- chemical- injury, NSAIDS, chronic reflux, alcohol
what are rare inflammatory disorders of the stomach
lymphocytic, eosinophillic, granulomatous
what are the inflammatory disorders of the stomach
acute and chronic gastritis, rare ones (lymphocytic. eosinophillic, granulomatous)
what is the pathology of autoimmune chronic gastritis
atrophy and intestinal metaplasia in body of stomach
why type of anaemia does autoimmune gastritis cause
pernicious anaemia, due to B 12 deficiency
how does autoimmune chronic gastritis affect nerves
causes SACDC- sub acute combined degeneration of the spinal chord
where is B12 absorbed
in the small intestine, bound to intrinsic factor
what is the most common type of chronic gastritis
H. pylori associated
what does H pylori look like on a gram stain
gram negative rod
how does H pylori affect the stomach
inhabits a niche between the epithelial cell surface and mucous barrier- excites early acute inflammatory response within gastric mucosa which destroys epithelial cells
what interleukin is essential in h pylori chronic gastritis
IL8
what produces anti pylori antibodies
lamina propria plasma cells
what does h pylori increase the risk of
duodenal ulcer, gastric ulcer, gastric carcinoma, gastric lympoma
what causes chemical gastritis
NSAIDs, alcohol, bile reflux (main 3)
direct injury to mucous layer by fat solvents
what is the pathology of chemical gastritis
marked epithelial regeneration, hyperplasia, congestion and little inflammation
what might chemical gastritis produce
erosions, ulcers
what is peptic ulceration
a breach in the GI mucosa as a result of acid and pepsin attack
what sites are predisposed to peptic ulcers
duodenum (1st part), stomach (junction of body and antrum), oesophago-gastric junction, stomal ulcers (jejunum mucosa)
describe the synergism that causes chronic duodenal ulcers
excess acid in duodenum produces gastric metaplasia which leads to H. pylori infection (failure of mucosal defence), inflammation, epithelial damage and ulceration
describe the morphology of peptic ulcers
2-10cm across, edges are clear cut and punched out
what does a peptic ulcer look like microscopically
layers:
- necrotic fibrinopurulent debris
- inflamed granulation tissue
- fibrotic scar tissue
what issue does scarring in peptic ulcers cause
strictures
what are the complications of peptic ulcers
perforation, penetration, haemorrhage, stenosis, intractable pain
what are two benign gastric tumours
hyperplastic polyps,
cystic fundi gland polyps
what are three malignant gastric tumours
carcinomas (adeno)
lymphomas
gastrointestinal stromal tumours
what is the pathogensis of gasrtic adenocarcinoma
- H. pylori infection
- chronic gastritis
- intestinal metaplasia/ atrophy
- dysplasia
- carcinoma
what other premalignant conditions can cause gastric adenocarcinomas
pernicious anaemia, partial gastrectomy (surgery creates inflammation), HNPCC/ lynch syndrome, menetriers disease
what are the two subtypes of gastric adebicarcinomas
intestinal- exophytic/polypoid mass
diffuse- expands/ infiltrates stomach wall
describe the morphology of intestinal type gastric adenocarcinoma
rolled edges- malignant ulcers, epithelial edges brought up, cancer in centre
what is the difference in morphology between benign and malignant peptic ulcers
benign is more punched out and lacks a raised rolled edge
what forms in intestinal type adenocarcinoma
glands- clusters of malignant cells
where is leatherbottel stomach seen
in diffuse gastric adenocarcinoma
what type of gastric adenocarcinoma has signet rings
diffuse
what has a better prognosis intestinal or diffuse
intestinal
what is MALT
mucosa associated lymphoid tissue
what is the pathogenesis of gastric lymphoma
Continuous inflammation induces an evolution into a clonal B-cell proliferation…low grade lymphoma
If unchecked evolves into a high grade B-cell lymphoma
associated with H pylori infection
