Alimentary Tract Pathology

Question 1

What types of cells are present in the mucosa of the small bowel?

Answer 1

Goblet cells
Columnar absorptive cells
Endocrine cells

Question 2

The myenteric plexus is formed of what?

Answer 2

Meissener’s plexus

Auerbach’s plexus

Question 3

Where is Meissener’s plexus located?

Answer 3

Base of the submucosa

Question 4

Where is Auerbach’s plexus located?

Answer 4

Between inner (circular) and outer (longitudinal) layers of muscularis propria

Question 5

What is the definition of idiopathic inflammatory bowel disease?

Answer 5

Chronic inflammatory conditions from inappropriate and persistent activation of mucosal immune system in presence of NORMAL intraluminal flora

Question 6

Which diseases make up the largest portion of Idiopathic bowel disease?

Answer 6

Crohn’s disease

Ulcerative Colitis

Question 7

Where is Crohns disease spread limited to?

Answer 7

Any part of GIT

Question 8

Where is Ulcerative colitis disease spread limited to?

Answer 8

Limited to colon

Question 9

What is the cause of idiopathic inflammatory bowel disease?

Answer 9

Exaggerated immune response vs gut flora
Genetics
?Defects in the mucosal barrier

Question 10

What gene mutation is associated with Crohns disease?

Answer 10

NOD2

Question 11

What gene mutation is associated with Ulerative Colitis?

Answer 11

HLA

Question 12

How is IBD diagnosed?

Answer 12

Clinical history
Radiograph examination
?pANCA

Question 13

A positive pANCA test is more likely in which IBD patients?

Answer 13

Ulcerative Colitis

Question 14

Ulcerative colitis is most common in which age groups?

Answer 14

20-30yrs, 70-80yrs

Question 15

Ulcerative colitis can often be localised where?

Answer 15

Rectum (proctitis)

Question 16

Ulcerative colitis more commonly spreads in which way?

Answer 16

Proximal

“backwash ileitis”

Question 17

What is the histological presentation of Ulcerative Colitis?

Answer 17

NO GRANULOMAS
Inflamed mucosa, crypts
Crypt absesses, disarray
Mucosal atrophy

Question 18

Atypical flat epithelium caused by UC can lead to what?

Answer 18

Adenomatous change leading to invasive cancer

Question 19

How does pancolitis effect cancer rates?

Answer 19

If greater than 10 years - it increases the likelihood 20-30x

Question 20

What is toxic dilation?

Answer 20

Colonic swelling due to gas production in ulcerative colitis

Question 21

What are the complications of Ulcerative Colitis?

Answer 21

Haemorrhage
Perforation
Toxic dilation

Question 22

Crohn’s disease is more common in which group

Answer 22

Women
20-30 years
White
Jewish

Question 23

How do GIT lesions differ in Crohns disease and ulcerative colitis?

Answer 23

Ulcerative colitis - lesions spread out from a point

Crohns disease - lesions skip from point to point

Question 24

How does Crohns disease effect the GIT?

Answer 24

Granular serosa
Wrapping mesenteric fat
Thickened, fibrotic mesentery
Lumen narrowing, wall thickened

Question 25

What is the histological presentation of Crohn's disease?

Answer 25

``` NON-CASEATING GRANULOMAS Cryptitis/crypt abscesses Deep ulceration 'chain of pearl' inflammation Fibrosis ```

Question 26

How do granulomas appear in UC vs CD?

Answer 26

UC - no granulomas | CD - non-caseating granulomas

Question 27

Long term features of Crohn's disease

Answer 27

``` Malabsorption Strictures Fistulas, abscesses Perforation 5x increased cancer risk ```

Question 28

How does inflammation appear in UC vs CD?

Answer 28

UC - Mucosa only | CD - Transmural

Question 29

Ischaemic enteritis is caused by what?

Answer 29

Acute occlusion of 1 of the 3 major enteric vessels

Question 30

Which part of the LI is most vulnerable to acute ischaemia?

Answer 30

Splenic flexure

Question 31

Histological presentation of acute intestinal ischaemia

Answer 31

``` Oedema Interstitial haemorrhage Sloughing necrosis Indistinct nuclei (Initial) absence of inflammation ```

Question 32

Which part of the GIT is most commonly effected by radiation colitis?

Answer 32

Rectum (pelvic radiotherapy)

Question 33

Which cells are targeted by radiation colitis?

Answer 33

Actively dividing cells Blood vessels Crypt epithelium

Question 34

Symptoms of radiation colitis

Answer 34

``` (Mimics IBD) Anorexia Abdominal cramps Diarrhoea Malabsorption ```

Question 35

What is the cause of appendicitis?

Answer 35

Obstruction

Question 36

Large Bowel Neoplasia can be what?

Answer 36

Dysplasia (adenoma) | Malignancy

Question 37

What are the main types of adenoma (polyps)?

Answer 37

Tubular Villous Tubulovillous

Question 38

What is the histological presentation of low grade dysplasia?

Answer 38

Increased nuclear no. Increased nuclear size Reduced mucin

Question 39

What is the histological presentation of high grade dysplasia?

Answer 39

Carcinoma in situ Crowded, irregular Not YET invasive

Question 40

The majority of colorectal carcinomas are what?

Answer 40

Adenocarcinoma

Question 41

What are the risk factors for colorectal adenocarcinoma?

Answer 41

Lifestyle Family history IBD (UC & CD) Genetics (FAP, HNPCC, Peutz-Jeghers)

Question 42

Pancolitis increases the risk of what?

Answer 42

Colorectal cancer (20-30x)

Question 43

Why does right sided bowel cancer tend to present late?

Answer 43

More water in bolus on right, so it moves round any blockage more easier than on left (descent) (Less symptomatic)

Question 44

How does right side colorectal adenocarcinoma present?

Answer 44

``` Polypoid Anaemia Vague pain Weakness Obstruction (less severe) ```

Question 45

How does left side colorectal adenocarcinoma present?

Answer 45

Annular Bleeding Changed bowel habit Obstruction