Pathology of the Small Intestine

Question 1

Describe the histology slide of a healthy small intestine

Answer 1

Villi are 3-4x as high as crypts and contain immune cells

Question 2

What are the two main causes of ischaemia of the small intestine?

Answer 2

Mesenteric artery occlusion

Non-occlusive perfusion insufficiency

Question 3

What causes mesenteric artery occlusion?

Answer 3

Mesenteric artery atherosclerosis

Thromboembolism

Question 4

What causes non-occlusive perfusion insufficiency?

Answer 4

Shock
Strangulation obstructing venous return
Hyperviscosity

Question 5

Explain the effect of hypoxia on the small intestine

Answer 5

As the mucosa is the most metabolically active, it is most sensitive to hypoxia.
As hypoxia goes on, the greater the depth of damage to the intestine wall - increased likelihood of gangrene

Question 6

Name some complications of ischaemia of the small intestine

Answer 6

Resolution
Fibrosis
Gangrene
Peritonitis
Sepsis
Death

Question 7

Explain Meckel’s diverticulum and the symptoms it may cause

Answer 7

Meckel’s diverticulum is an incomplete regression of the vitello-intestinal duct
It is remembered by the rule of two’s - tubular duct, 2 inches long, 2 feet above IC valve, affects 2% of people
May cause bleeding, perforation or diverticulitis although usually asymptomatic

Question 8

Name the primary tumours of the small intestine

Answer 8

Lymphomas
Carcinoid tumours
Carcinomas

Question 9

Describe lymphomas of the small intestine and their treatment

Answer 9

They are rare and are all non-Hodgkins

They are treated by surgery and chemotherapy

Question 10

Give the characteristics and usual location for carcinoid tumours

Answer 10

Carcinoid tumours are small, yellow and slow-growing

They are commonly found in the appendix

Question 11

Name the common symptoms of carcinoid tumours

Answer 11

Flushing, headaches and diarrhoea

Question 12

Name the appearance and associated diseases of carcinomas

Answer 12

Carcinomas are identical to colorectal cancer

They are associated with Crohn’s disease and coeliac disease

Question 13

Where do secondary tumours of the small intestine metastasise from?

Answer 13

Ovary
Colon
Stomach

Question 14

What are the causes of appendicitis?

Answer 14

Idiopathic
Faecoliths
Lymphoid hyperplasia
Parasites
Tumours

Question 15

Describe the different pathologies of appendicitis

Answer 15

Acute inflammation by neutrophils
Mucosal ulceration
Serosal congestion
Pus in lumen

Question 16

What are some symptoms of appendicitis?

Answer 16

Vomiting
Abdominal pain
Right iliac fossa tenderness

Question 17

Name complications of appendicitis

Answer 17

Peritonitis
Rupture
Abscess
Fistula
Sepsis and liver abscess

Question 18

What is the cause of coeliac disease?

Answer 18

Gliadin (component of glucose) triggers an abnormal T cell response within the small intestine epithelium
This leads to flattened villi and coeliac disease

Question 19

What does coeliac disease have a strong association with?

Answer 19

HLA-B8
Dermatitis hepetiformis
Childhood disease

Question 20

What tests can be carried out to determine coeliac disease?

Answer 20

Duodenal biopsy

Serology

Question 21

How does coeliac disease affect the bowel’s normal function?

Answer 21

It causes malabsorption of sugars, fats, amino acids, water and electrolytes

Question 22

What are the symptoms of coeliac disease?

Answer 22

Loss of weight
Anaemia
Abdominal bloating
Failure to thrive
Vitamin deficiencies