pathology of the gut

Question 1

what is Barrett’s oesophagus?

Answer 1

• Distal oesophagus is lined by columnar ells due to metaplasia; the oesophagus is lined by gastric mucosa, which can develop goblet cells in another process termed intestinal metaplasia

Question 2

what are the risks factors? BO? 5

Answer 2

• High BMI
• Alcohol drinking
• Tobacco smoking
• Drugs which relax the lower oesophageal sphincter
• Familial/genetic predisposition

Question 3

describe the pathogenesis of BO? 4

Answer 3

• Reflux of acidic contents from the stomach into the oesophagus leads to reflux oesophagitis
• Squamous epithelium changes to columnar epithelium in a process of metaplasia
• The metaplastic process is an adaptation to injury caused by the gastric contents
• Columnar epithelium increases the risk of adenocarcinoma of the oesophagus through precancerous stage called dysplasia

Question 4

describe the pathogenesis of Barrett’s associated carcinoma? 7

Answer 4

• Squamous epithelium
• Reflux oesophagus
• Gastric epithelium
• Intestinal metaplasia
• Low grade dysplasia
• High grade dysplasia
• Adenocarcinoma

Question 5

describe normal large bowel mucosa? 3

Answer 5

• The crypts are arranged in a row reminiscent of test tubes
• The goblet cells are full of mucin
• The crypts are separated by the lamina propria with vessels and connective tissue

Question 6

describe ulcerative colitis in the large bowel/? 2

Answer 6

• Inflammation confined to the mucosa

- Crypt architecture distortion

Question 7

what are the risk factors for dysplasia in UC? 4

Answer 7

• UC at an early age
• Total UC- involving the whole large bowel
• Repeated bouts of acute inflammation with short periods of remission
• Long duration with UC; patients with total UC for 8 years require annual surveillance colonoscopy to look for dysplasia

Question 8

what is transmural inflammation?

Answer 8

• involves the full thickness of the bowel wall

Question 9

describe diverticular diseases? 7

Answer 9

• Outpouchings as a result of the herniation of the mucosa and submucosa through the bowel wall at sites of weakness
• Common in the populations on low fibre diet
• 95% affect the sigmoid colon
• Can be complicated with diverticulitis and perforation-> peritonitis
• Can present with intestinal obstruction
• Can mimic cancer
• Colo-vesical fistula and patient presents with pneumaturia

Question 10

what can faecal impaction and inflammation lead to? 2

Answer 10

• perforation

- peritonitis

Question 11

what type of epithelium lines the oesophagus?

Answer 11

non keratinised stratified squamous epithelium

Question 12

what is metaplasia?

Answer 12

when one type of mature cell turns into another type of mature cell

Question 13

what causes metaplasia in the oesophagus?

Answer 13

abnormal stimulus due to gastric contents going into the stomach

Question 14

how does a patient present with oesophageal cancer?

Answer 14

Struggling to swallow which will worsen over time due to growing obstruction, starts with solids then liquids

Question 15

name 4 features of coeliac disease?

Answer 15

• Villi atrophy,
• chronic inflammation of the lamina propria,
• crypt hyperplasia,
• increase in intra-epithelial lymphocytes

Question 16

what are the complications of coeliac disease? 4

Answer 16

• Refractory to treatment,
• cancers of small bowel, large bowel and pancreas,
• osteoporosis,
• infertility

Question 17

what are the other conditions associated with coeliac disease? 5

Answer 17

• Dermatitis herpetiformis,
• primary biliary cirrhosis,
• autoimmune hepatitis,
• type 1 DM,
• autoimmune thyroiditis

Question 18

what are the indications for colectomy in UC? 5

Answer 18

Refractory to treatment 
Toxic megacolon 
Severe bleeding 
High grade dysplasia 
cancer

Question 19

what are the symptoms of strictures in the small or large bowel?

Answer 19

abdominal pain due to intestinal obstruction

Question 20

what are the complications of Crohn’s disease? 4

Answer 20

• intra-abdominal abscess,
• sinus tract formation,
• fistulas (patient will present with pneumaturia/ air or gas in the urine is it is colo- vesical),
• cancer