pathology of the stomach Flashcards
name 3 inflammatory disorders of the stomach
acute gastritis
chronic gastritis
rare: lymphocytic, granulomatous, osinophillic
what can cause acute gastritis?
arritant chemical injury severe burns shock severe trauma head injury
what can casue chronic gastritis?
autoimmune
bacterial
chemical
what dos autoimmune chronic gastritis do?
due to immune system prodicing antibodies against own stomach lining (parietal cells) causing atrophy
what can autoimmune chronic gastritis cause?
atrophy and intestinal metaplasia in body of stomach
pernicious anaemia, macrocytic due to B12 deficiency
increased risk of malignancy
SACD
what are the symptoms of autoimmune chronic gastritis?
tiredness
staggering gate
what is the most common type of chronic gastritis?
H. pylori associated
what happens in H. pylori chronic gastritis?
bacteria inhibits a niche between epithelial cel surface and mucous barrier
Excites early acute inflammatory response
If not cleared then a chronic active inflammation
ensues
IL8 is involved
what type of bacteria is H. pylori?
gram -ve curvilinear rod
what can H. pylori associated chronic gastritis increase the risk of?
Lamina propria plasma cells produce anti H.pylori antibodies
Increases risk of Duodenal ulcer
Increases risk of Gastric Ulcer
Increases risk of Gastric carcinoma
Increases risk of Gastric lymphoma
do the H. pylori invade the stomach?
no, just sit and irritate the epithelium
what can cause chemical gastritis?
NSAIDs
alcohol
bile reflux
direct injury to mucous layer by fat solvents
how does injury to mucous layer by fat solvents cause chemical gastritis?
Marked epithelial regeneration, hyperplasia, congestion and little inflammation
May produce erosions or ulcers
what does chemical gastritis look like?
red with lots of lesions
what is peptic ulceration?
a breach in the gastrointestinal mucosa as a result of acid and pepsin attack
a discontinuity in epithelial surface?
tend to be chronic an deep
where are chronic peptic ulcers likely to appear?
duodenum
stomach
oesopho-gastric junction
stomal ulcers
what is the pathogenesis of chronic duodenal ulcers?
50% have increased aci secretion or inappropriately sustained secretion of acid
excess acid in duodenum produces gastric metaplasia and leads to H. pylori infection, inflammation, epithelial damage and ulceration
Basically increased attack and failure of defence due to wrong type of epithelia (metaplasia)
describe the morphology of peptic ulcers
2-10cm across
edges are clear cut and punched out
what do peptic ulcers look like microscopically?
loayed appearance
floor of necrotic fibrinopurulent debris
Base of inflamed Granulation tissue
Deepest layer is fibrotic scar tissue
list 6 possible complications of peptic ulcers
perforation penetration haemorrhage stenosis intractable pain
what are benign gastric tumours? what do they do?
polyps
hyperplastic or cystic fundic gland polyps
Cause heaps of cells that sit on the lining but don’t cause problems
what types of malignant tumours can arise in the stomach?
carcinomas
lymphomas
adenocarcinomas
Gastrointestinal stromal tumours (GISTs) = rare
who gets gastric adenocarcinomas
japan, china, Columbia, finland
what can cause gastric adenocarcinoma?
H. pylori can increase risk
what is the pathogenesis of adenocarcinoma?
H. pylori infection > chronic gastritis > intestinal metaplasia/atrophy > dysplasia > carcinoma
what other pre-malignant conditions can pre-dispose to gastric adenocarcinoma?
pernicious anaemia
partial gastrectomy
HNPCC/lynch syndrome (genetic)
menetrier’s syndrome
what are the 2 subtypes of gastric adenocarcinoma?
Intestinal type…exophytic/polypoid mass
Diffuse type…expands/infiltrates stomach wall
what does intestinal type adenocarcinoma look like histologically?
produces glands
what does diffuse type adenocarcinoma look like physically?
thicker, rigid stomach wall
what does diffuse type adenocarcinoma look like histologically?
forms signet rings
diffuse sheet of malignant cells
which subtype of adenocarcinoma has the better prognosis?
intestinal
where can gastric adenocarcinoma spread to?
locally = directly to other organs
Lymph nodes: omental
Haematogenous: to liver and beyond
Transcoelomic: into peritoneal cavity and ovaries (kruckenberg)
where are gastric lymphomas (maltoma) derived from?
mucosa associated lymphoid tissue (MALT)
what infection is gastric lymohoma associated with?
H. pylori
what happens in 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
