20 - Pathology of the GI Tract - 1 Flashcards Preview

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Flashcards in 20 - Pathology of the GI Tract - 1 Deck (33):
1

Oesophagitis classification

Acute or chronic

2

Oesophagitis aetiology

Infectious - bacterial, viral, fungal
Chemical - ingestion of corrosive substance, refleux

3

Risk factors for reflux oesophagitis

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

4

Types of hernia

Sliding hiatus
Para-oesophageal

5

Sliding hiatus hernia will give what symptoms?

Reflux

6

Para-oesophageal hernia has one big risk what is it

Strangulation - necrosis of tissue due to pinching

7

Histology of reflux oesophagitis

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

Also, inflammatory cell infiltration

8

Complications of reflux oesophagitis

Ulceration
Haemorrhage
Perforation
Benign stricture
Barrett's oesophagus

9

Cause of barrett's oesophagus - what risk factors?

Longstanding reflux
Same risk factors

10

Macroscopy of barrett's oesphagus

Proximal extension of the sqaumo-columnar junction.

Squamous mucosa replaced by columnar mucosa

11

Barrett's oesophagus types of columnar mucosa

Gastric cardia type or gastric body type

Intestinal type = specialised barrett's mucosa

12

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

Increased risk of adenocarcinoma

Regular endoscopic surveillance is recommended for early detection of neoplasia

13

Two histological types of oesophageal carcinoma

Squamous cell carcinoma
Adenocarcinoma

14

Adenocarcinoma localisation, macroscopy, spread and staging

Lower oesphagus

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

Same as squamous cell carcinoma

15

Aetiology of chronic gastritis

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

16

What does H.pylori do?

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

17

H.pylori complications

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

No atrophy -> MALT lymphoma

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

18

Acute gastric ulcer histology

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

19

Chronic gastric ulcer histology

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

20

Complications of peptic ulcer

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

21

SLIDE 39

Copy table!

22

Gastric cancer frequency comparison

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

23

Carcinoma of GOJ

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

24

Carcinoma of gastric body/antrum

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

25

Macroscopic subtypes

Superficial exophytic
Flat or depressed
Superficial excavated
Exophytic
Linitis plastica
Excavated

26

Histological subtypes

Scattered growth
Non-scattered growth
Diffuse type
Intestinal type

27

What does HDGC stand for?

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

28

Coeliac disease features

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

29

Pathogenesis of coeliac disease

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

30

Coeliac disease diagnosis is hard - why?

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

31

Coeliac disease - clinical features

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

32

Diagnosis of coeliac disease

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

Tissue biopsy is diagnostic

33

Treatment of coeliac

Gluten-free diet

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