A3- Gastrointestinal Pathology

Question 1

What is Histopathology?

Answer 1

Branch of medicine concerned with the study of changes within tissues associated with disease.

Typically involves using a microscope to examine tissue samples removed from a patient to provide a diagnosis to guide clinical management.

Question 2

Specimen journey

• The specimen is obtained, placed in 10%
_____ _______ ______ and transported
to the lab.

Answer 2

Specimen journey
• The specimen is obtained, placed in 10%
neutral buffered formalin and transported
to the lab.

Question 3

Formalin is a ‘fixative’

What does this mean?

Answer 3

links protein molecules together to make tissues rigid and prevent decay. Also ‘kills’ pathogens making the tissue biologically inert

Question 4

What happens to the speciemen in the labortatory?

Answer 4

• The specimen is booked in
• Placed in a numbered cassette
• Processed through formalin, alcohol, xylene and paraffin wax
• Embedded in a wax block
• Sectioned and mounted on a glass slide
• Stained

Question 5

What happens after a specimen is stained

Answer 5

a report is produced

Question 6

What is metaplasia?

Answer 6

Reversible transformation from one type of mature adult tissue to another

Question 7

What is dysplasia?

Answer 7

Potentially reversible process where cells acquire genetic abnormalities which may ultimately lead on to cancer.
Classified on the basis of morphology as low or high grade

Question 8

Malignant tumours

What does proliferation mean?

Answer 8

– Independent of the initiating stimulus

Question 9

Malignant tumours

What does invasion mean?

Answer 9

– Beyond muscularis mucosae
– Gives potential to access vessels and lymphatics

Question 10

Malignant tumours

What does metastasis mean?

Answer 10

– Spread to organs beyond site of origin
– Blood, lymph nodes, transcoelomic

Question 11

WHat are the three basic layers of the GI tract

Answer 11

– Mucosa – epithelium + lamina propria (superficial layer)
– Submucosa
– Muscularis propria

Question 12

Oesophagus is lined with

Answer 12

Squamous epithelial lining

Question 13

What type of surface is there in the Duodenum for absorption

Answer 13

villous

Question 14

Duodenum has what kind of glands?

Answer 14

Brunner’s gland

Question 15

Stomach is lined with…

– Specialised body type with _____ ____
– Non-specialised ___ ____

Answer 15

– Specialised body type with parietal cells
– Non-specialised antral type

Question 16

Answer 16

Question 17

Explain what you see in the red arrow compared to black arrow

Answer 17

black arrow shows normal basal layer (normal squamous epilethilum)

red arrow head (glandular epiethilum)

Question 18

What is a classic presentation of Barrett’s Oesophagus

Answer 18

Middle aged to elderly white males with raised BMI and a
history of reflux disease and hiatus hernia.

Question 19

Barretts is a major risk factor for?

Answer 19

Major risk factor for adenocarcinoma hence screening programmes exist BUT have similar mortality rates to general population, death from oesophageal adenocarcinoma is rare and those being screened may present with interval carcinomas.

Question 20

Diagnosing Barrett’s?

Answer 20

• Gold standard diagnostic tool is endoscopy
• Normal distal squamous epithelium has been replaced by metaplastic columnar epithelium, which is clearly visible endoscopically >1cm above the GOJ

Question 21

How do you report barretts

Answer 21

• Barrett’s oesophagus with gastric metaplasia only
• Barrett’s oesophagus with intestinal metaplasia
• No evidence of Barrett’s oesophagus

Question 22

Barretts dysplasia (rare) can be classified as?

Answer 22

• Endoscopically visible or not
• Classified as indefinite, low grade or high grade

Question 23

What grade is this barretts

Answer 23

high grade

Question 24

What does this show

Answer 24

inflammatory cells between the globlet cells

Question 25

What are the histological features of gastritis?

Answer 25

– Inflammation – acute/chronic/granulomatous
– Helicobacter
– Intestinal metaplasia
– Gland atrophy
– Dysplasia/malignancy

Question 26

Types of gastritis?

Answer 26

• Acute/erosive - alcohol
• Drug induced – NSAID’s, iron pills
• Ischaemia
• Radiation
• Infection (other than HP)
• Autoimmune
• Helicobacter pylori
• Chemical/reflux

Question 27

Complications of HP gastritis?

Answer 27

• Peptic ulcer disease – 15-20% lifetime risk in those with
infection.

• Gland atrophy – intestinal metaplasia – gastric
carcinoma (linked to up to 70% of cases).

• Stimulation of mucosal associated lymphoid tissue –
extranodal marginal zone lymphoma (MALToma)

Question 28

What is the generic tumour type called of these cell origins.

Epithelial

Lymphoid

Mesenchymal

Melanocyte

Mesothelial

Answer 28

Question 29

What disease is the most common cause of malabsorption in Western
populations

Answer 29

Coeliac disease

Question 30

• Serological tests: for Coeliac disease

Answer 30

– tTGA – highest sensitivity
– EMA – almost absolute specificity

Question 31

Coeliac Tx

Answer 31

Treatment/outcome
– Excellent prognosis on gluten free diet
– Ongoing symptoms with poor compliance
– Risk of developing lymphoma