Pathology of the upper GI tract Flashcards
3 main conditions of oesophageal pathology
gastro-oseophageal reflux
Barrett’s oseophagus
Oseophageal carcinoma.
what is the epithelial lining of (most of) the oesophagus
squamous epithelium
what are the names of the 2 oesophageal sphincters
cricopharyhgeal- upper end
Gastro-oseophageal- lower end.
what is the epithelial lining of the lower 1.5-2 cm of the oesophagus
glandular columnar
what is the length of the oesophagus
25 cm
where is the squamo-columnar junction located
about 40 cm from the incisor teeth.
what 3 histological layers can be found in the oesophagus
mucosa- stratified squamous epithelium
submucosa-blood vessels
Muscularis Propria- muscle for contraction
define oesophagitis
inflammation of the oesophagus
what causes oesophagitis
infection-bacterial, viral (HSV, CMV), fungal
chemical- ingestion of a corrosive substance, reflux of gastric contents.
commonest cause of oesophagitis
reflux of gastric acid or bile
risk factors for developing oesophagitis
defective lower oesophageal sphincter
hiatus hernia
increased intra-abdominal pressure
increased gastric fluid volume due to gastric outflow stenosis
define hiatus hernia
abnormal bulging of a portion of the stomach through the diaphragm
2 types of hiatus hernia
sliding hernia- reflux symptoms
paraoesophageal hernia- strangulation, separate part of the stomach which requiresblood supply and as it does not receive it becomes necroized.
what histiological chafes occur in reflux oesophgitis
basal hyperplasia, elongation of papillae, increased cell desquamatation
lamina propria- inflammatory cells infiltrate.
complications of reflux oesophagi tis
ulceration- wearing of epithelium
haemorrages- goes through blood vessels.
perforation- goes through oesophageal wall.
benign stricture- where fibrosis occurs for healing.
barrett’s oesophagus
what is the main cause of barrett’s oesophagus
longstanding reflux
what is the main histological change in barrette’s oesophagus
proximal extension of the squamocolumnar junction.
squamous mucosa replaced by columnar mucosa.
what is the main difference between squamous and columnar epithelium
column epithelium is more glandular (mucous secreting glands)- process is known as glandular metaplasia
what are the 3 types of columnar mucosa in the GI
gastric cardia type
gastric body type
intestinal type= specialised barrett’s mucosa.
what is the main histiologically difference (in terms of cells) in between intestinal and gastric epithelium
Contains goblet and paneth cells
what condition can barrett’s oesophagus predispose toe
adenocarcioma.
what is the pathogenesis to get from barrette’s oesophagus to adenocarcinoma
barrett’s oesophagus- basal rounded nuclei, goblet cells.
low grade dysplasia- nuclei are rounded and have goblet cells.
high grade dysplasia
Adenomcarcinoma- cells break through the basement membrane
2 histiological subtypes of oesophageal carcinoma
squamous cell
adenocarcinoma
Other than barrette’s oesophagus name 2 other causes of adenocarcionoma
tobacco, obesity
which part of the oesophagus does adenocarcinoma occur?
lower, upper or middle
lower
what is the macroscopic appearance of adenocarcinoma
plaque like, nodular, fun gating, ulcerated, depressed, infiltrating, polypoidal (protrudes into lumen), stricture
What are the main risk factors of squamous carcinoma
– Tobacco and alcohol – Nutrition (potential sources of nitrosamines) – Thermal injury (hot beverages) – HPV – Male – Ethnicity (black) •
which part of the oesophagus is shamus cell carcinoma
lower, upper or middles
upper and middle
what is the pathogenesis of shamus carcinoma
preceded by squamour dysplasia- nuclei are atypical and enlarged, mitosis rise towards the surface, but the basement membrane is not yet breached.
once basement membrane breached becomes carcinoma.
what are the macroscopic features of squamous cell carcinoma
ulcerative, stricture, polypoidal.
what staging is used for oesophageal tumours
TNM staging
What are the 3 main conditions which affects the gastric system
chronic gastritis
peptic ulceration
gastric carcinoma.
4 anatomical regions of the stomach
cardia, fundus, body, antrum
3 histological regions of the body
cardia, body and antrum
what causes increased aggression upon the gastric lining e.g. increased stomach acidity
excessive alcohol, drugs, heavy smoking, corrosive, radiation, chemotherapy, infection.
what causes the stomach lining defences to become impaired
ischaemia, shock, delayed emptying, duodenal reflux, impaired regulation of pepsin secretion
what 2 types of ulcers does H pylori cause
duodenal
gastric
what type of bacteria is H pylori
• Gram negative spiral shaped bacterium
main causes of peptic ulcer
– Hyperaciditiy – H.pylori infection – Duodeno- gastric reflux – Drugs- NSAID’s – Smoking
which layers do peptic ulcers form in
mucosa and submucosa
what are the main sites where peptic ulcers forms
first part of duodenum
junction of antral and body mucosa
distal oesophagus
what is the histology of a acute gastric ulcer
full thickness coagulative necrosis of mucosa
covered with ulcer slough- (necrotic debris, fibrin and neutrophils.)
Granulation tissue at ulcer floor
haemorrage.
what is the histology of a chronic gastric ulcer
clear cut edges overhang the base
extensive granulation and scar tissue on ulcer floor
scarring often throughout the entire gastric wall with breaching of muscularis propria
bleeding
what are the main complications of peptic ulcers
haemorrage
perfonation-peritonitis
penetration into a organ
stricturing- hour glass deformity (stomach is in 2 separate parts due to narrow stricture between them).
what causes a gastric adenocarcinoma
– Diet (smoked/cured meat or fish, pickled vegetables)
– Helicobacter pylori infection
– Bile reflux (e.g. post Billroth II operation)
– Hypochlorhydria (allows bacterial growth)
– ~1% hereditary
Is carcinoma of the gastro-oesophageal junction caused by H-pylori and diet
No
is carcinoma of the gastric body or antrum associated with H pylori and diet
Yes
what is used to treat H pylori
PPI’s
what are the macroscopic subtypes of gastricadenocarcinoma
- Superficial exophytic
- Flat of depressed
- Superfical excavated
- Exophytic
- Linits plastic
- Exacvated
what are the main 2 histological subtypes of gastric adenocarcinoma
• Scattered growth- diffuse (spreads) type (signet ring cell carcinoma)- POORLY DIFFERENTIATED
– Common in hereditary or lintis plastica.
• Non scattered type – intestinal type (tubular adenocarcinoma), forms glands like intestinal tumour.- WELL DIFFERENTIATED.
what mutation results in Hereditary diffuse type gastric cancer (HDGC)
• Germline CDH1/E-cadherin mutation
what molecule contains most of the disease producing part of coeliacs disease
gliadin
– Induces epithelial cells to express IL-15
what is the pathogenesis of coeliacs
gliadin induces epithelial cells to express IL-15.
this activates proliferation of CD8 and IELs.
These are cytotoxic and kill enterocytes.
what are the 3 different types of clinical presentation of coeliac
silent disease-positive serology/ villous atrophy but no symptoms
Latent disease- positive serology but no villous atrophy
Symptomatic patients- • Anaemia, chronic diarrhoea, bloating, or chronic fatigue
what tests are used to determine coeliacs
• IgA antibodies to tissue transglutaminase (TTG)
• IgA or IgG antibodies to deamidated gliadin
• Anti-endomysial antibodies - highly specific but less sensitive
biopsy before and after gluten free diet.
treatment for coeliacs
– Gluten-free diet à symptomatic improvement for most patients
