CP20 - Pathology of GI Tract Flashcards
what is the normal histology of oesophagus?
squamous epithelium
what is the sphincter call at the upper end of oesophagus?
cricopharyngeal sphincter
what is the sphincter call at the bottom of oesophagus?
it is called the gastro-oesophageal junction
what is the normal histology of the area after the gastro-oesophageal junction?
glandular (columnar) mucosa
what is the squamo-columnar junction located?
located at 40 cm from the incisor teeth
what are the 3 layers of the oesophagus?
mucosa, submucosa, muscularis propria
what is oesophagitis?
inflammation of the oesophagus
what is the aetiology of oesophagitis?
infection - bacterial, viral (HSV1, CMV), fungal (candida)
chemical - corrosive substances, reflux of gastric contents
what are the 2 main types of oesophagitis?
acute and chronic
what is the commonest form of oesophagitis?
reflux oesophagitis
what is reflux oesophagitis?
Caused by reflux of gastric acid (gastro-oesophageal reflux) and/or bile (duodeno-gastric reflux)
what are some of the risk factors for reflux oesophagitis?
- Defective lower oesophageal sphincter
- Hiatus hernia
- Increased intra-abdominal pressure
- Increased gastric fluid volume due to gastric outflow stenosis
what is the commonest clinical symptom for reflux oesophagitis?
heartburn
what is the histological changes in reflux oesophagitis?
squamous epithelium will undergo basal cell hyperplasia, elongation of papillae and increase cell desquamation, there is also inflammatory cell infiltration
what are some of the complications for reflux oesophagitis?
ulceration, haemorrhage, perforation, benign stricture (segmental narrowing), Bareet’s oesophagus
what are the causes of Barrett’s oesophagus?
longstanding reflux
what is the macroscopic finding of the Barrett’s oesophagus
Proximal extension of the squamo-columnar junction
what is the histological finding of the Barrett’s oesophagus
Squamous mucosa replaced by columnar mucosa > “glandular metaplasia”
what are the different types of columnar mucosa?
gastric cardia, gastric body, intestinal type
what type of columnar mucosa is characteristic for Barrett’s mucosa
intestinal type - normally only found in the stomach
what is barett’s disease premalignant condition of
adenocarcinoma
what is the pathological progression from barett’s disease?
BO - low-grade dysplasia - high- grade dysplasia - adenoma
what are the 2 main types of oesophageal carcinoma?
squamous cell carcinoma (native squamous cells), adenocarcinoma (arise from barrett’s)
what are some of the risk factors oesophageal adenocarcinoma?
Male, caucasians, industrialised countries
aetiology for oesophageal adenocarcinoma?
barett’s oesophagus
where does oesophageal adenocarcinoma normally arise?
lower oesophagus junction
what are the different subtype for oesophageal adenocarcinoma?
plaque-like, nodular, fungating, ulcerated, depressed, infiltrating,
what are the risk factor of oesophageal squamous carcinoma?
Tobacco and alcohol – strong link Nutrition (potential sources of nitrosamines) Thermal injury (hot beverages) HPV Male Ethnicity (black)
where does oesophageal squamous carcinoma normally arise?
middle and lower 1/3 of oesophagus
what is the pre-malignant stage of oesophageal squamous carcinoma?
squamous dysplasia
What staging system does oesophageal cancer use
TMN
what is pT staging in the staging for oesophageal cancer stand for?
depth of invasion of the primary tumour
what is the N in TMN for oesophageal cancer stand for?
regional lymph nodes
what does the M in TMN oesophageal cancer stand for?
distant metastasis
what are the different parts for stomach
cardic (right below the GOJ), body (below cardia), fundus (head of stomach), antrum (right next to duodenum)
what are some of the major cause for gastritis?
- increased aggression (Excessive alcohol
- Drugs
- Heavy smoking
- Corrosive
- Radiation
- Chemotherapy
- Infection)
- impaired defences (Ischaemia - Shock - Delayed emptying - Duodenal reflux - Impaired regulation of pepsin secretion)
what is the acronym for the major causes for chronic gastritis
A (autoimmune), B (Bacterial infection - H.polyri), C (chemical injury)
where in the stomach is more likely for H.pylori to be presence
in the antrum
how does H.pylori cause chronic gastriitis?
Damages the epithelium leading to chronic inflammation of the mucosa
what is the possible outcome for H.pylori infection?
Results in glandular atrophy, replacement fibrosis and intestinal metaplasia
where are the major sites for peptic ulcer?
First part of duodenum Junction of antral and body mucosa Distal oesophagus (GOJ)
what are the main aetiology factor for peptic ulcer?
Hyperacidity H. pylori infection Duodeno-gastric reflux Drugs (NSAIDs) Smoking
what are the histological changes for acute gastric ulcer
Full-thickness coagulative necrosis of mucosa (or deeper layers)
Covered with ulcer slough (necrotic debris + fibrin + neutrophils)
Granulation tissue at ulcer floor
what are the histological changes for chronic gastric ulcer
- Clear-cut edges -overhanging the base
- Extensive granulation and scar tissue at ulcer floor
- Scarring often throughout -the entire gastric wall with breaching of the muscularis propria
- Bleeding
what are the complication for peptic ulcers
haemorrhage ( acute and /or chronic - anaemia)
perforation - peritonitis
penetration into an adjacent organ (liver, pancreas)
stricturing - hour glass deformity
what are the different subtypes of gastric cancer
adenocarcinoma, endocrine tumours, MALT lymphomas, stromal tumours (GIST)
which is the most common gastric cancer
gastric adenocarcinoma
what is the aetiology for gastric adenocarcinoma
Diet (smoked/cured meat or fish, pickled vegetables)
Helicobacter pylori infection
Bile reflux (e.g. post Billroth II operation)
Hypochlorhydria (low level of HCL produced allows bacterial growth)
~1% hereditary
features of carcinoma of GOJ
White males
- Association with GO reflux
- No association with H. pylori / diet
features of gastric body/antrum
Association with H. pylori
- Association with diet (salt, low fruit
& vegetables)
- No association with GO reflux
what are the macroscopic subtypes of gastric adenocarcinoma
superficial exophytic, flat/depressed, superficial excavated, exophytic (invaded to musclaris level), linitis plastica (total infiltration), excavated
refer to slides
what are the 2 histological subtypes of gastric adenocarcinoma
diffuse type (signet ring cell carcinoma), intestinal type (tubular adenocarcinoma)
d - ring
i - tube
what does HDGC
hereditary diffuse type gastric cancer (HDGC)
what else can coeliac disease be known as?
coeliac sprue/gluten sensitive enteropathy
what is enteropathy
a disease of intestine, especially small intestine
what is the pathology of coeliac disease
reaction to Gliadin (a component of gluten) which induce epithelial cells to express IL-15
IL-15 - activate CD8+ intraepithelial lymphocytes which are cytotoxic and kill enterocytes
what cancer can coeliac disease lead to?
small intestine adenocarcinoma
