GIT Flashcards
A barium swallow shows a lesion in the upper oesophagus. What is the most likely cause? (August 2014)
a. Schatzki ‘A’ ring
b. Vertical shelf
c. Adenocarcinoma
d. Barret oesophagus
Schatzki A ring: smooth ring just above the gastro-oesophageal junction
- Physiological contraction of the muscle - A few cm proximal to the B ring
Schatzki B ring: located at the gastro-oesophageal junction
- Seen in the setting of hiatus hernia - Represents the junction of the squamous and columnar epithelium - Usually 1-3mm in length
Vertical shelf: ?oesophageal web or prominent cricopharyngeus muscle (seen in the proximal oesophagus)
Adenocarcinoma: stricture with an irregular (ulcerated) surface, applecore lesion
Barrett oesophahus: long segment stricture in the mid-lower oesophagus
- Reticular mucosal pattern with thickened folds - Associated with reflux
ANSWER: Unclear. A vertical shelf may refer to oesophageal webs and cricopharyngeal bars which are located in the upper oesophagus.
Which is an association? (March 2015)
a. Oesophageal web with graft vs host disease
b. Oesophageal ring with peripheral neuropathy
c. Corkscrew oesophagus with obesity
Oesophageal webs
- Oesophageal constriction caused by a thin mucosal membrane projecting into the lumen (thoracic oesophagus)
- Most common in middle aged females
- Usually incidental, but can cause dysphagia and food regurgitation if there is severe stenosis
- Typically arise from the anterior wall (never the posterior wall); Can be circumferential; Occasionally multiple
Associations: Plummer-Vinson syndrome GvHD GORD – especially if in the distal oesophagus External beam radiation
Schatzki ring:
- Symptomatically narrow oesophageal B-ring (GOJ)
- Symptoms depend on the degree of narrowing:
• <13mm always symptomatic
• 13-20mm sometimes symptomatic
• >20mm rarely symptomatic
- Occurs in the distal oesophagus and usually occurs with a hiatus hernia
o Associated oesophageal conditions: Hiatus hernia Reflux oesophagitis Oesophageal web Oesophageal diverticulum
ANSWER: Oesophageal webs are associated with GvHD
Which is true regarding the oesophagus? (March 2016)
a. Traction diverticuli affect the mid-oesophagus
b. Schatzki rings affect the mid-oesophagus
ANSWER: Traction diverticuli affect the mid-oesophagus. Schatzki rings affect the lower oesophagus
What organ should not be biopsied with GvHD?
a. Kidney
b. Colon
c. Oesophagus
d. Liver
e. Skin
Graft vs Host disease
- Usually bone marrow or stem cell transplantation
- Initiation of T cell mediated destruction
Main targets:
Host immune cells (as patients are immunosuppressed)
Biliary epithelium (causing jaundice)
Skin (desquamative rash)
Gastrointestinal (GI watery diarrhea and bleeding)
o GvHD in the liver: Acute: • Hepatitis • Chronic vascular inflammation • Intimal proliferation • Bile duct destruction Chronic: • Portal tract inflammation (usually eosinophil mediated) • Bile duct destruction • Fibrosis
ANSWER: The kidney is not centrally involved in GvHD, and therefore should not be biopsied
Which is the least likely option regarding achalasia? (March 2016)
a. Decreased tone in the upper/mid oesophagus
b. Decreased tone in the distal oesophageal sphincter
c. Trypanosoma cruzi is a cause of secondary achalasia
Achalasia
- Failure of organized peristalsis and impaired relaxation of the LOS
- Results in marked dilatation of the oesophagus and food stasis
- Distal segment of narrowing is less than 3.5cm
Classification:
Primary: idiopathic
Secondary: assoc w Chagas disease (Trypanosoma cruzi)
Pathology:
- Loss of peristalsis: Abnormality of the Auerbach plexus (or the vagus nerve or the dorsal motor nucleus)
- Loss of relaxation of the lower oesophageal sphincter:
May be normal tone early in the disease
Complications: Oesophageal carcinoma (5%) Aspiration pneumonia Candida oesophagitis Acute airway obstruction (rare)
DDx:
- Central and peripheral neuropathy
- Scleroderma: GOJ is open, oesophageal dilation is less severe
- Oesophageal malignancy or gastric carcinoma (pseudoachalasia)
- Oesophageal stricture
- Chagas disease (secondary achalasia)
- Anti-Hu antibodies (lung cancer)
- Diffuse oesophageal spasm
- Presbyoesophagus
ANSWER: Decreased tone in the distal oesophagus is the least likely option, as achalasia is characterized by increased tone at the lower oesophageal sphincter
Which is correct regarding Barrett oesophagus? (March 2014)
a. Predisposes to adenocarcinoma
ANSWER: Barrett oesophagus predisposes adenocarcinoma following intestinal metaplasia of the epithelium
What is true of Barrett oesophagitis? (August 2016)
a. Metaplastic columnar epithelium
Barrett oesophagus
o intestinal metaplasia of the oesophagus
o precursor lesion to adenoCa of the oesophagus
Epidemiology:
- 3-15% of patients w GORD
- Mean age at diagnosis – 55
- 37% of patients with scleroderma have Barrett oesophagus
- 30x increased risk of developing oesophageal adenoCa
Pathology:
- progressive metaplasia of the oesophageal stratified squamous epithelium to columnar epithelium
ANSWER: Barrett oesophagus is characterized by metaplastic columnar epithelium
A binge drinker experiences pain on swallowing. A barium study shows a nodular distal oesophagus. (March 2015)
a. Reflux
b. Carcinoma
c. Varices
d. Caustic injury
• Varices should be painless • Barrett’s oesophagus risk factors: - Long standing reflux - Hiatus hernia - Alcohol consumption
ANSWER: Reflux
Which is not considered a risk factor for oesophageal adenocarcinoma and squamous cell carcinoma? (March 2016)
a. Smoking
b. Alcohol
c. Obesity
d. H pylori
e. Hot beverages
- Smoking: risk for SCC and adenocarcinoma
- Alcohol: risk for SCC and adenocarcinoma
- Obesity: risk for adenocarcinoma
- Hot beverages: risk for SCC
ANSWER: H pylori is not a risk factor for oesophageal carcinoma – some studies imply it is protective
Which is not associated with trisomy 21? (August 2014)
a. Pyloric stenosis
b. Imperforate anus
c. Hirschprungs disease
Gastrointestinal associations with T21: o Anal atresia o Coeliac disease o Duodenal atresia o Hirschprung disease o Omphalocoele
ANSWER: Pyloric stenosis is not associated with trisomy 21
Which is false of autoimmune gastritis? (March 2015)
a. Associated with microcytic anaemia
b. Associated with subacute combined degeneration of the cord
c. Associated with carcinoid
d. High gastrin
Atrophic gastritis
- Divided into autoimmune (type A) and non-autoimmune (type B)
Type A (autoimmune):
- Gastric body and fundus atrophy secondary to antiparietal cell antibodies
- Decreased secretion of acid & intrinsic factor -> vitamin B12 deficiency (pernicious anaemia)
o Macrocytic anaemia
o Subacute combined degeneration of the cord
- High serum gastrin
Associations:
• Carcinoid tumours
• 3 times more likely to develop gastric neoplasms
Type B (non-autoimmune) - Gastric antrum atrophy Causes: • Helicobacter pylori (most common) • Alcohol • NSAID use • Bile salt reflux
ANSWER: Autoimmune gastritis is not associated with a microcytic anaemia (associated with a macrocytic anaemia)
What is the most common complication of H. pylori? (September 2013)
a. Duodenal ulcer
b. Gastric ulcer
c. Adenocarcinoma
d. MALT lymphoma
e. Metaplasia
H. pylori causes chronic gastritis which can persist for decades
Complications of H. pylori: o Gastric and duodenal ulcers (10-20%) - H. pylori is responsible for 90% of DU and 70-80% of gastric ulcers o Gastric adenoCa (2%) o Gastric MALT lymphoma (1%)
Metaplasia
o More common in the duodenum
o Meta-analysis suggests incidence from 20-40% in patients w chronic gastritis
ANSWER: Evidence suggests that intestinal metaplasia is the most common complication, secondary to chronic gastritis
Regarding peptic ulcer disease, which is most likely? (March 2014)
a. Greater curvature lesions are associated w NSAIDs
b. Gastric MALToma is associated with …
c. H. pylori has tropism (tendency) towards the duodenal mucosa
d. Duodenal ulcers are more common than gastric ulcers
- 95% of gastric ulcers occur at the lesser curvature of the stomach
- Greater curvature ulcers are more likely to be associated with NSAID use
- DU are more common than stomach ulcers (4:1)
- Duodenal ulcers are almost universally associated with H. pylori infection
- Gastric MALT lymphoma is associated w H. pylori
- In early cases, treatment of H. pylori may lead to regression of the lymphoma
ANSWER: Greater curvature ulcers are associated with NSAID use; H. pylori is almost universally associated with duodenal ulceration. It seems to be more common in gastric mucosa, however but can be present in the abnormal duodenum. MALToma is associated with H. pylori. ?question could be which is false
H. pylori is associated with: (August 2014)
a. Gastric cancer
b. Mantle cell lymphoma
c. Decreased vitamin B12
d. Hyperplastic polyps
e. Duodenal villous atrophy
ANSWER: Gastric cancer is associated with H. pylori (2%). MALT lymphoma is associated in 1%. Hyperplastic polyps are seen in Zollinger-Ellison.
Which is H. pylori not associated with? (March 2017)
a. Gastric cancer/carcinoma
b. Gastric lymphoma
c. GIST
d. Gastric ulcers
e. Gastritis
ANSWER: H. pylori is not associated with GIST
Which is least likely to cause cancer of the stomach? (March 2017)
a. Cronkhite-Canada
b. Peutz-Jegher
c. Hyperplastic polyps
d. Sporadic/fundal gland polyp
e. Atrophic gastritis
ANSWER: Cronkhite-Canada syndrome is least likely to cause cancer of the stomach
Diffuse thickening of the stomach rugae with preservation of the architecture. (August 2016, September 2013)
a. MALT lymphoma
b. Diffuse type adenocarcinoma (Linitis plastica)
c. Intestinal type adenocarcinoma
d. GIST
e. Carcinoid
Mucosa associated lymphoid tissue (MALT) lymphoma
- aka extranodal marginal zone B-cell lymphoma
- Low grade extranodal lymphoma
Epidemiology:
7.5% of non-Hodgkin’s lymphoma
Mean age 60 years
Slight female predominance
Pathology:
- Arise in epithelial tissues where lymphoid cells are usually not found
- Chronic infection/inflammation has been implicated e.g. stomach and H. pylori infection; Sjogren syndrome and salivary gland
- <10% transform to high grade disease
- Can metastasize to other sites or bone marrow
Sites:
• Stomach – most common (33-50%) (H. pylori in 90%)
• Intestine (5%) - Possible association w Coeliacs
• Salivary glands (Sjogren’s)
• Skin
• Thyroid (Hashimoto’s)
• Others: orbit, breast, lung and upper airways, kidney, liver, rectum and prostate
Gastric lymphoma
o Primary or secondary - MALT lymphoma accounts for 60%
o Most common site of extranodal lymphoma (25%
Epidemiology: 6th decade, no gender predilection
Pathology (MALT):
90% association with H. pylori
May spontaneous regress following treatment
- Variable appearance including thickened gastric rugae and linitis plastica
ANSWER: MALT lymphoma
Gastric cancer is most associated with: (August 2016)
a. Bilroth I
b. Bilroth II
c. Roux en y
Risk factors for gastric cancer: o H. pylori infection o Pernicious anaemia o Adenomatous gastric polyps o Atrophic gastritis o Bilroth II partial gastrectomy (for benign disease) - Reflux of bile & pancreatic juices into the stomach is thought to be carcinogenic o Type A blood group
ANSWER: Bilroth II
Regarding GIST, which is true? (March 2014)
a. Stomach GIST are the most maligant
b. Leiomyomas are associated with MEN syndrome
c. Recurrence of GIST is related to the initial size
GIST:
o Most common mesenchymal tumours of the gastrointestinal tract. Responsive to chemotherapy
Pathology:
- Arise from the interstial cells of Cajal
- 95% stain positive for c-KIT – tyrosine kinase growth factor receptor
• Can be targeted with chemotherapy (Glivec/imatinib)
- Smaller lesions and lesions located in the stomach demonstrate less aggressive behaviour
- Round lesions with frequent haemorrhage
- Larger lesions may have central necrosis and cystic degeneration
Associations:
- Carney triad: extra-adrenal paragangliomas, GIST tumours and pulmonary chondroma
- NF1
Locations:
Stomach – 70% (less aggressive behaviour when compared to lesions elsewhere)
Small intestine – 20-25%
Anorectum – 7%
Colon
Oesophagus
Extra-gastrointestinal GISTs – mesentery, omentum and retroperitoneum
Prognosis:
- Tx: en bloc resection & chemoTx
- Local recurrence was more common before the introduction of tyrosine kinase inhibitors
- 50% have metastases at presentation
ANSWER: Considering larger lesions are more aggressive, it could be inferred that local recurrence risk is increased with larger tumours.
Which is true regarding HIV? (March 2015)
a. CMV colitis is associated with apthous ulcers
CMV infection of the GI tract is seen in severely immunocompromised patients e.g. solid organ transplantation and HIV
- Most common gastrointestinal manifestation of AIDS (30% of AIDS patients during their illness)
- CMV oesophagitis, gastritis, enteritis or colitis
o CMV colitis:
Sigmoid colon and rectum are the most commonly involved sites; oesophagus also common
Associated with multiple mucosal ulcerations
Other opportunistic infections in AIDS patients:
o Pneumocystis jiroveci: pneumonia
o Candidiasis (most common fungal infection)
o Atypical mycobacterium
o TB
o Cryptococcus: meningitis
o Toxoplasma: encephalitis (50% of mass lesions in the CNS)
o JC virus: PML
o HSV: mucocutaneous ulcerations in the oral and genital regions
o Cyptosporidium
ANSWER: CMV colitis is associated with apthous ulcers (shallow ulcerations)
What is the second most common cause of GI atresia? (March 2015)
a. Duodenal
b. Ileal
c. Caecal
d. Anal
- Ileal - 1 in 1000
- Anal – 1 in 5000
- Duodenal – 1 in 5000 – 10000
- Caecal – rare
ANSWER: Anal atresia is the second most common
Colonic membranes are associated with: (April 2013, September 2013, August 2016, March 2017)
a. Pseudomembranous colitis and ischaemia
b. Pseudomembranous colitis and ischaemic colitis
c. Inflammatory bowel disease and dysentery
Ischaemic bowel disease
o Mucosal or mural infarction – may follow chronic or acute hypoperfusion
o Transmural infarction – usually follows acute vascular occlusion. All three layers of the wall
Microscopic:
- Atrophy or sloughing of the surface epithelium
- Inflammatory infiltrates usually initially absent in acute ischaemia (Neutrophils recruited within hours of reperfusion)
- Chronic ischaemia is accompanied by fibrous scarring of the lamina propria. Occasionally results in stricture formation
- Bacterial superinfection (acute or chronic ischaemia) can result in pseudomembrane formation secondary to enterotoxin release (Resembles c. diff colitis)
ANSWER: Colonic membranes are associated with pseudomembranous colitis and ischaemic (in the setting of bacterial superinfection)
Which is least likely to cause small bowel ischaemia? (March 2017)
a. Acute myocardial infarction
b. SMA atherosclerosis
c. SMA embolism
d. Polyarteritis nodosa
e. Behcet disease
ANSWER: Behcet disease – causes ulceration of the mucosa, may present with GI bleeding
In severe small bowel ischaemia, which is the most frequent association? (April 2013)
a. Tight atherosclerotic narrowing of the SMA origin
b. Hypotension
c. Aortic dissection
d. Narrowing of the coeliac trunk origin
e. Polyarteritis nodosa
Most common causes of SMA occlusion: o Embolic – 60% o Atherosclerotic – 30% o Dissection o Slow flow/idiopathic
**Robbins: Mucosal or mural infarction is caused by acute or chronic hypoperfusion o Cardiac failure o Shock o Dehydration o Use of vasoconstrictive drugs
Transmural infarction: acute vascular obstruction
o Severe atherosclerosis
o Aortic aneurysm
o Hypercoagulable states
o Oral contraceptive use
o Embolisation: Cardiac vegetations; Aortic atheromas
ANSWER: Atherosclerosis would be the most common. Atherosclerosis is (however) a more common cause of chronic ischaemia.
