Pathology of the GI Tract

Question 1

What epithelium lines the oesophagus?

Answer 1

Squamous

Question 2

What epithelium lines the oesophagus below the diaphragm?

Answer 2

Glandular (columnar) epithelium

Question 3

What are the two oesophageal sphincters?

Answer 3

1) Cricopharyngeal

2) Gastro-oesophageal

Question 4

Define: Oesophagitis

Answer 4

Acute/Chronic inflammation of the oesophagus

Question 5

What type of Oesophagitis is the most common?

Answer 5

Reflux

Question 6

What are the causes of Oesophagitis?

Answer 6

> Gastro-oesophageal reflux

> Duodeno-gastric (bile) reflux

Question 7

What are the risk factors for Oesophagitis?

Answer 7

> Incr intra-abdominal pressure
Weak lower spincter
Hiatus hernia (stomach into thoracic cavity)
Gastric outflow stenosis –> increase fluid

Question 8

What is the characteristic symptom of Reflux Oesophagitis?

Answer 8

Heartburn

Question 9

What are the complications of Reflux Oesophagitis?

Answer 9

> Ulceration
> Haemorrhage
> Peforation
> Barrett's Oesophagus
> Benign stricture

Question 10

What is a hiatus hernia?

Answer 10

When a part of the stomach abnormally protrudes through the diaphragm

Question 11

What symptoms does a sliding hiatus hernia give?

Answer 11

Reflux symptoms

Question 12

What symptoms does a para-oesophageal hernia give?

Answer 12

Strangulation

Question 13

What occurs to the squamous epithelium in Reflux Oesophagitis?

Answer 13

> De-squamed

> Basal cell hyperplasia

Question 14

What occurs to the lamine propria in Reflux Oesophagitis?

Answer 14

Infiltrated by inflammatory cells.

Question 15

What is Barrett’s Oesophagus?

Answer 15

It is a premalignant condition assc with adenocarcinoma development.

Question 16

What is the cause of Barrett’s Oesophagus?

Answer 16

Chronic Reflux

Question 17

What are the risk factor’s for Barrett’s Oesophagus?

Answer 17

Male, Caucasian and overweight

Question 18

What is macroscopically seen in Barrett’s Oesophagus?

Answer 18

An extension of the squamo-columnar junction

Question 19

What is the histologically characteristic mark of Barrett’s Oesophagus?

Answer 19

Glandular metaplasia - Squamous to Columnar.

Question 20

What is the process from Barrett’s Oesophagus to Adenocarcinoma?

Answer 20

Barrett’s Oesophagus –> Low grade dysplasia –> High grade dysplasia –> Adenocarcinoma

Question 21

What two types of Oesophageal carcinoma are there?

Answer 21

> Squamous cell carcinoma

> Adenocarcinoma

Question 22

Who is Adenocarcinoma higher in M or F? And by what ratio?

Answer 22

Males 7:1

Question 23

In the oesophagus where are said carcinomas localised:

1) Squamous cell carcinoma
2) Adenocarcinoma

Answer 23

1) Upper and middle third

2) Lower

Question 24

What are the risk factors for Squamous Carcinoma?

Answer 24

> Tobacco and alcohol
Nutrition (nitrosamines)
HPV
Hot thermal injury

Question 25

What precedes Squamous Carcinoma?

Answer 25

Sqaumous dysplasia

Question 26

What are each of the components of TNM tumour staging?

Answer 26

``` pT = Primary tumour invasion depth N = Regional lymph node M = Distant metastatis ```

Question 27

What level does pT1 invade to?

Answer 27

Muscularis Mucosae or Submucosa

Question 28

What level does pT2 invade to?

Answer 28

Muscularis Propria

Question 29

What level does pT3 invade to?

Answer 29

Adventitia

Question 30

To where does pT4 invade to?

Answer 30

Adjacent tissues

Question 31

How many lymph nodes are invaded in pN2,3 and 4?

Answer 31

1) 1- 2 2) 3-6 3) 7+

Question 32

What is the ABC of chronic gastritis aetiology?

Answer 32

Autoimmune, Bacterial, Chemical Injury

Question 33

Explain the pathological mechanisms and histiological findings of Autoimmune chronic gastritis?

Answer 33

Pathological Mechanism: > Anti-parietal > Anti-intrinsic factor antibodies > Sensitised T cells Histiological Findings: > Atrophied Gastric body > Intestinal Metaplasia

Question 34

Explain the pathological mechanisms and histological findings of Bacteria caused Chronic Gastritis?

Answer 34

``` Pathological Mechanisms: > Release cytokines > Liberate chemokines > Release mucolytic enzymes > Bacterial urease --> ammonia production > Immune response does tissue damage. ``` Histological findings: > Active chronic inflammation > Intestinal metaplasia > Multifocal atrophy

Question 35

Explain the pathological mechanisms and histological findings of chemical injury caused Chronic Gastritis?

Answer 35

Pathological mechanism: Direct injury Histological findings: Foveolar hyperplasia

Question 36

What type of bacterium is H.Pylori?

Answer 36

Gram negative spiral shaped

Question 37

Where is H.Pylori mostly found?

Answer 37

Antrum > body

Question 38

How does H.Pylori cause chronic inflammation?

Answer 38

Damaged epithelium lining.

Question 39

What is a peptic ulcer?

Answer 39

A submucosal localised lesion

Question 40

What are the major sites of a peptic ulcer?

Answer 40

> First part of the duodenum > Body-antrum mucosal junction > Gastro-oesophageal junction

Question 41

What are the main causes of a peptic ulcer?

Answer 41

``` > Smoking > Drugs > Duodeno-gastric reflux > Hyperacidity > H.Pylori infection ```

Question 42

What are the complications of a peptic ulcer?

Answer 42

> Perforation perionitis > Haemorrhage > Penetration into adjacent organs > Stricture into hourglass shape

Question 43

What is the most frequent type of gastric cancer?

Answer 43

Adenocarcinoma

Question 44

What is the incidence of gastric adenocarcinoma?

Answer 44

5th most common cancer but declining

Question 45

What causes gastric adenocarcinoma?

Answer 45

> H.Pylori > Diet (smoked meats, pickled veg) > Bile refluex > Hypochlorhydria - 1% hereditary

Question 46

What mutation can cause hereditary diffuse type gastric cancer?

Answer 46

Germline CDH1/E-cadherin mutation

Question 47

What is Coeliac disease?

Answer 47

= Gluten sensitive enteropathy (small intestine disease)

Question 48

What is the incidence of Coeliac disease?

Answer 48

0.5-1% general population

Question 49

What is Gliadin, how does it work?

Answer 49

It is the part of gluten that can induce disease. | Induces epithelial cells to produce inter-leukin 15.

Question 50

What is the pathogenesis mechanism of Coeliac Disease?

Answer 50

Gliadin stimulates epithelial cells --> release IL5. IL5 activates CD8 and IEL --> They kill enterocytes

Question 51

What diseases are associated with Coeliac?

Answer 51

> Dermatitis Herpatiformis - 10% of pt's | > Lymphocytic colitis/gastritis

Question 52

What cancers are assc with Coeliac?

Answer 52

> Enteropathy-associated T cell lymphoma. | > Small intestine adenocarcinoma

Question 53

What tests are done for Coeliac disease?

Answer 53

> IgA against Tissue transglutaminase (TTG) > IgA/IgG against deaminated Gliadin > Anti-endomysial antibodies - v specific but less sensitive