20 - Pathology of the GI Tract - 1

Question 1

Oesophagitis classification

Answer 1

Acute or chronic

Question 2

Oesophagitis aetiology

Answer 2

Infectious - bacterial, viral, fungal

Chemical - ingestion of corrosive substance, refleux

Question 3

Risk factors for reflux oesophagitis

Answer 3

Defective lower oesophageal sphincter
Hiatus hernia
Increased intra-ab pressure
Increased gastric fluid volume due to gastric outflow stenosis

Question 4

Types of hernia

Answer 4

Sliding hiatus

Para-oesophageal

Question 5

Sliding hiatus hernia will give what symptoms?

Answer 5

Reflux

Question 6

Para-oesophageal hernia has one big risk what is it

Answer 6

Strangulation - necrosis of tissue due to pinching

Question 7

Histology of reflux oesophagitis

Answer 7

Basal cell hyperplasia with elongated papillae and desquamation - lost overlying epithelial layer in severe cases (increased bleeding risk)

Also, inflammatory cell infiltration

Question 8

Complications of reflux oesophagitis

Answer 8

Ulceration 
Haemorrhage
Perforation
Benign stricture
Barrett's oesophagus

Question 9

Cause of barrett’s oesophagus - what risk factors?

Answer 9

Longstanding reflux

Same risk factors

Question 10

Macroscopy of barrett’s oesphagus

Answer 10

Proximal extension of the sqaumo-columnar junction.

Squamous mucosa replaced by columnar mucosa

Question 11

Barrett’s oesophagus types of columnar mucosa

Answer 11

Gastric cardia type or gastric body type

Intestinal type = specialised barrett’s mucosa

Question 12

Barrett’s oesophagus is a premalignant condition -what do we do?

Answer 12

Increased risk of adenocarcinoma

Regular endoscopic surveillance is recommended for early detection of neoplasia

Question 13

Two histological types of oesophageal carcinoma

Answer 13

Squamous cell carcinoma

Adenocarcinoma

Question 14

Adenocarcinoma localisation, macroscopy, spread and staging

Answer 14

Lower oesphagus

Plaque-like, nodular, fungating, ulcerated, depressed, infiltrating

Same as squamous cell carcinoma

Question 15

Aetiology of chronic gastritis

Answer 15

Autoimmune
Bacterial (h.pylori)
Chemical injury
NSAIDs
Bile reflux
Alcohol

Question 16

What does H.pylori do?

Answer 16

Lives on epithelial surface protected by the overlying mucus barrier
Damage leads to chronic inflammation
More common in antrum

Question 17

H.pylori complications

Answer 17

Corpus - hypochlorhydria -> atrophy/metaplasia -> gastric ulcer/cancer

No atrophy -> MALT lymphoma

Antral -> hypergastrinaemia -> hyperchlorhydria -> pre-pyloric gastric ulcer -> gastric metaplasia -> duodenal ulcer

Question 18

Acute gastric ulcer histology

Answer 18

Full-thickness coagulative necrosis of mucosa
Covered with ulcer slough
Granulation tissue at ulcer floor

Question 19

Chronic gastric ulcer histology

Answer 19

Clear-cut edges overhanging base
Extensive granulation + scar tissue
Scarring often throughout entire gastric wall
Bleeding

Question 20

Complications of peptic ulcer

Answer 20

Haemorrhage
Perforation -> peritonitis
Penetration into an adjacent organ (liver, pancreas)
Stricturing -> hour-glass deformity

Question 21

SLIDE 39

Answer 21

Copy table!

Question 22

Gastric cancer frequency comparison

Answer 22

Most: adenocarcinoma
Less: endocrine, MALT lymphoma, stromal tumours

Question 23

Carcinoma of GOJ

Answer 23

White males
Association with GO reflux
No association with H.pylori/diet
Increased incidence in recent years (obesity)

Question 24

Carcinoma of gastric body/antrum

Answer 24

H.pylori association
Association with diet (salt, low fruit/veg
No association with reflux
Less incidence in recent years

Question 25

Macroscopic subtypes

Answer 25

``` Superficial exophytic Flat or depressed Superficial excavated Exophytic Linitis plastica Excavated ```

Question 26

Histological subtypes

Answer 26

Scattered growth Non-scattered growth Diffuse type Intestinal type

Question 27

What does HDGC stand for?

Answer 27

Hereditary diffuse type gastric cancer | Germline CDH1/E-cadherin mutation

Question 28

Coeliac disease features

Answer 28

Immune mediated enteropathy Ingestion of gluten containing cereals - wheat, rye, barley Genetic 0.5% to 1%

Question 29

Pathogenesis of coeliac disease

Answer 29

1. Gliadin is alcohol soluble component of gluten induces epithelial cells to make IL-5 2. IL-15 produced by epithelium 3. Activates CD8+ 4. They are cytotoxic and kill enterocytes Note: CD8 does not recognise gliadin directly hence pathway = gliadin-induced IL-15 secretion pathway

Question 30

Coeliac disease diagnosis is hard - why?

Answer 30

Silent disease Latent disease (30-60yo) Symptomatic patients - anaemia, chronic diarrhoea, bloating, chronic fatigue

Question 31

Coeliac disease - clinical features

Answer 31

No gender pref Other disease associations - Dermatitis herpetiformis (10%); lymphocytic gastritis and lymphocytic colitis Coeliac disease associated with enteropathy-associated T-cell lymphoma + small intestinal adenocarcinoma

Question 32

Diagnosis of coeliac disease

Answer 32

Non-invasive serologic test: IgA Ab to tissue transglutaminase; IgA or IgG to deamidated gliadin Tissue biopsy is diagnostic

Question 33

Treatment of coeliac

Answer 33

Gluten-free diet