Histo: Upper GI Disease Pt.2

Question 1

List some causes of acute gastritis

Answer 1

Chemical: NSAIDS, alcohol, corrosives
Infection: H pylori

Question 2

List some causes of chronic gastritis

Answer 2

• Autoimmune (e.g. pernicious anaemia, anti-parietal cell) - affects body
• Bacterial (H. pylori) - affects antrum
• Chemical (NSAIDs, bile reflux) - affects antrum

NOTE: the key inflammatory cells in chronic gastritis are lymphocytes

Question 3

What is mucosa-associated lymphoid tissue and what is their presence indicative of?

Answer 3

• Chronic gastritis caused by H. pylori infection induces lymphoid tissue in the stomach
• The presence of lymphoid follicles in a stomach biopsy, is highly suggestive of H. pylori infection
• This is important because it is associated with an increased risk of lymphoma

Question 4

What are some complications of H. pylori gastritis

Answer 4

• Adenocarcinoma
• MALT lymphoma

H. pylori asscoaited with 8x increased risk of gastric cancer

Question 5

Name a key virulence factor that enables H. pylori to cause chronic infection.

Answer 5

Cag-A positive H. pylori has a needle-like appendage that injects toxins into intercellular junctions allowing bacteria to attach more easily

Question 6

List some other cause of gastritis.

Answer 6

• CMV
• Strongyloides
• Crohn’s disease

Question 7

What are the two pathways that lead to the development of GI cancer?

Answer 7

• Metaplasia-Dysplasia pathway (e.g. oesophageal cancer)
• Adenoma-Carcinoma pathway (e.g. colon cancer)

Question 8

Define gastric ulcer.

Answer 8

A break in the gastric mucosa. The depth of the loss of tissue goes beyond the muscularis mucosa (into the submucosa)

NOTE: if you only get loss of surface epithelium with or without involvement of the lamina propria then it is an erosion

Question 9

What is the difference between acute and chronic ulceration?

Answer 9

Chronic ulcers are accompanied by scarring and fibrosis

Question 10

What must you do with all gastric ulcers?

Answer 10

They should all be biopsied to rule out malignancy.

Question 11

List some complications of gastric ulcers.

Answer 11

Bleeding - anaemia; massive haemorrhage and shock

Perforation - peritonitis

Question 12

What type of cancer is gastric cancer?

Answer 12

• 95% adenocarcinoma
• 5% squamous cell carcinoma, lymphoma (MALToma), gastrointestinal stromal tumour (GIST), neuroendocrine tumours

Question 13

What are the two main morphological subtypes of gastric adenocarcinoma? What are their key features?

Answer 13

• Intestinal: well-differentiated, presence of gland producing mucin
• Diffuse: poorly differentiated, composed of single cells with no attempt at gland formation

Question 14

Name two types of diffuse adenocarcinoma of the stomach.

Answer 14

• Linitis plastica
• Signet ring cell carcinoma

Question 15

What is the overall survival rate of gastric cancer?

Answer 15

15%

Question 16

What is gastric lymphoma/MALToma? How is it treated?

Answer 16

• Lymphoma of the gastric mucosa that is driven by chronic inflammation (H. pylori gastritis)
• Consists of lots of B lymphocytes (marginal zone)
• Treatment: if limited to stomach and H. pylori present - H. pylori eradication

NOTE: if H. pylori is also present, crypts may also contain neutrophils

Question 17

What causes duodenitis and duodenal ulcers?

Answer 17

• Caused by increased acid produced in the stomach that spills into the duodenum
• It can also occur due to chronic inflammation and gastic metaplasia with H. pylori infection

Question 18

List some other pathogens that affect the duodenum.

Answer 18

• CMV
• Cryptosporidium
• Giardiasis
• Whipple’s disease (Tropheryma whippelii)

Question 19

List some histological features of coeliac disease.

Answer 19

• Villous atrophy
• Crypt hyperplasia
• Increased intraepithelial lymphocytes (>20 per 100 enterocytes)

NOTE: the T cell response to gliadin in Coeliac disease is responsible for the damage to villi

Question 20

What is lymphocytic duodenitis?

Answer 20

• When you get the inflammatory changes (increased intraepithelial lymphocytes) without architectural changes
• Many people with this condition either have coeliac disease or will go on to develop coeliac disease

Question 21

How is coeliac disease diagnosed?

Answer 21

Antibodies: anti-tTG, anti-endomysial

Duodenal biopsy

NOTE: duodenal biopsy will be normal in people with coeliac disease who have been following a strict gluten-free diet

Question 22

Which other condition has very similar clinical and histological features to coeliac disease?

Answer 22

Tropical sprue

Question 23

What type of lymphoma is associated with coeliac disease

Answer 23

Enteropathy associated T cell lymphoma

NOTE: lymphomas in the stomach due to H. pylori are B cell lymphomas