Gastrointestinal Pathology

Question 1

What is Reflux Oesophagitis?

Answer 1

Most common abnormality of the oesophagus
Gastric acid from the stomach, when present in the lower oesophagus produces a burning pain in he centre of the lower chest
commonly referred to as heartburn

Question 2

What is Reflux Oesophagitis more commonly known as ?

Answer 2

Heartburn

Question 3

What are predisposing factors to for acid reflux?

Answer 3

Increased abdominal pressure
e.g. pregnancy, eating, repeated stooped posture
Hiatus Hernia
Smoking
Alcohol ingestion

Question 4

The normal squamous epithelium of the lower oesophagus is sensitive to the effect of gastric acid and is frequently damaged.
What complications may arise from this?

Answer 4

Reflux Oesophagitis (GORD – gastro- oesophageal reflux disease/ Heart burn)
The oesophageal mucosa become acutely inflamed.

Peptic ulceration of the lower Oesophagus
Small ulcers usually develop, which become chronic with fibrosis

Question 5

What is Lower oesophageal stricture?

Answer 5

Chronic peptic ulceration causes progressive fibrous thickening of the lower oesophagus wall.
This results in narrowing, which leads to difficulty swallowing.

Question 6

What is Barret’s Oesophagus?

Answer 6

Persistent oesophageal reflux causes metaplasia of the lower oesophageal mucosa and squamous epithelium being replaces by glandular epithelium composed of tall columnar ells
also termed columnar epithelial – lined oesophagus (CELO)

Can progress from metaplastic glandular epithelium to epithelial dysplasia
and then to adenocarcinoma
Therefore patients with Barret’s Oesophagus are monitored closely through regular endoscopy and biopsy to detect any early neoplastic changes.
treatment by oesophageal surgery is then possible before development of invasion.

Question 7

What is dysphagia?

Answer 7

The term used to describe difficulty swallowing.

Which can be due to many different causes including:
Swallowed foreign bodies – especially in children
Lesions in the wall – including neoplasms or fibrosis from chronic inflammation
Lesions outside of the wall – including oesophageal diverticulum tumours in the mediastinum
Lesions affecting function – motor neurone disease.

Question 8

What are Hiatus Hernia’s?

Answer 8

The upper part of the stomach moves through he diaphragmatic oesophageal hiatus into the thoracic cavity
a common condition
Patient’s complain of Symptoms of reflux
may have peptic ulceration in the intra thoracic part of the stomach and lower oesophagus

Two Types:
Sliding Hiatus Hernia:
The stomach herniates through the diaphragmatic hiatus through which the lower oesophagus normally passes

Paraesophageal Hiatus Hernia
The stomach protrudes through a separate duct alongside the oesophagus

Question 9

What are the two types of hiatus hernias?

Answer 9

Sliding Hiatus Hernia:
The stomach herniates through the diaphragmatic hiatus through which the lower oesophagus normally passes

Paraesophageal Hiatus Hernia
The stomach protrudes through a separate duct alongside the oesophagus

Question 10

What are the 3 mucosal zones of the stomach?

Answer 10

The cardia
which is immediately adjacent to the oesophageal junction

The Body
contains long tubular glands secreting acid & intrinsic factor

The Pylorus (aka antrum)
which contains the majority of gastrin secreting cells.

Each zone is affected by different pathology

Question 11

What is gastritis?

Answer 11

Inflammation of the gastric mucosa & submucosa
Can be either acute or chronic inflammation

Main types of Acute Gastritis :
Acute Gastritis
Superficial acute inflammation of the gastric mucosa
Mostly caused by ingested chemicals e.g. Alcohol, aspirin, NSAID’s

Acute Erosive Gastritis
Focal loss of superficial gastric epithelium
Patients develop dyspepsia with vomiting and hematemesis.
Most commonly caused by shock, stress associated with burns, raised intracranial pressure or very heavy acute alcohol ingestion

Question 12

What are the main types of acute gastritis?

Answer 12

Acute Gastritis
Acute Erosive Gastritis

Question 13

Chronic Gastritis Carries an increased risk of developing malignancy - True or false?

Answer 13

True

Question 14

What are the causes of chronic gastritis?

Answer 14

Helicobacter Pylori Associated Chronic Gastritis
Autoimmune Chronic Gastritis
Reactive Gastritis

Question 15

What is Helicobacter Pylori Associated Chronic Gastritis?

Answer 15

Most common form
H. Pylori colonise the surface of the epithelium beneath the thin layer of mucus.
Leads to epithelial damage and a mixed acute and chronic inflammatory cell reaction in the lamina propria & superficial epithelium.
Damage is most severe in the antrum, but also the fundus.
Intestinal metaplasia is frequently see, in which normal gastric epithelium is replaced by a type similar to that seen in the small intestine

Question 16

What is Autoimmune Chronic Gastritis ?

Answer 16

Associated with autoimmune disease – pernicious anaemia
generally seen in elderly patients due to atrophy of mucosa.
Those affects have antibodies against gastric parietal cells (90%) and intrinsic factor (60%).
The autoimmune damaged cells are unable to produce as much hydrochloric acid, and are unable to absorb dietary vitamin B12
The B12 deficiency leads to interference with normal erythropoiesis in the bone marrow, and therefore the patient develops pernicious anaemia.

Question 17

What is reactive gastritis?

Answer 17

aka Reflux gastritis
Occurs with duodenal fluid (which is alkaline) refluxes into the lower part of the stomach.
Common in people who have had previous gastric surgery.
Commonly seen after prolonged NSAID usage.

Question 18

What are common causes of acute gastritis?

Answer 18

NSAIDs
Smoking
Alcohol
Stress
Shock

Question 19

What are common causes of chronic gastritis?

Answer 19

Helicobacter Pylori
Excessive Smoking
Prolonged NSAID use

Question 20

What are consequences of chronic gastritis?

Answer 20

1. Intestinal metaplasia
   Normal epithelium is replaced.
   Cells may further undergo dysplasia and eventual transformation into a carcinoma.
   Therefore, patients with chronic gastritis (of any form) need to be regularly monitored.
2. Peptic Ulcer

Question 21

What are peptic ulcers?

Answer 21

Peptic ulcers are caused by damage to the gastric lining by gastric secretions especially Acid.

The gastric mucosa is normally protected by a mucus barrier containing acid resisting neutral glycoproteins and buffering bicarbonate ions.

Peptic ulceration occurs when protective mechanisms are deficient and persist because of gastric acid.

Can be either an Acute or Chronic Peptic Ulcer.

Question 22

Where can peptic ulcers occur?

Answer 22

oesophagus, stomach or duodenum.

Question 23

What is the most common cause of an oesophagus peptic ulcer?

Answer 23

Most commonly caused by Reflux acid from the stomach onto oesophageal mucosa.

Question 24

What is the most common cause of a stomach peptic ulcer?

Answer 24

Most commonly caused by H. Pylori infection or surface epithelial damage by NSAID’s.

Question 25

What is the most common cause of Duodenum peptic ulcer?

Answer 25

Most commonly caused by hypersecretion of stomach acid into the duodenal mucosa.

Question 26

What are acute peptic ulcers?

Answer 26

Usually develop from areas of erosive gastritis
Have the same risk factors / predisposing factors as acute & erosive gastritis: NSAID’s, Alcohol, stress, shock.. etc.

Acute Peptic ulcers may:
Cause severe bleeding
Heal completely without scarring, or
progress to form a chronic peptic ulcer.

Question 27

What are chronic peptic ulcers?

Answer 27

If Damaging stimulus persists:
Necrosis - organisation - repair all occur concurrently
PLUS specific immune system defences are activated around the damaged area (macrophages & lymphoid cells)
and therefore this state is termed chronic inflammation

The gastric mucosa is normally protected from adverse effects of HCL & proteolytic enzymes
If the mechanisms are broken down, the acid & enzymes destroy the epithelium & supporting stroma.
This damaging stimulus is persistent  As acid & enzymes are constantly produced
Tissue damage stimulates an active inflammatory response, with the formation of exudate close the damaging acid in the stomach.
In the depths of the ulcer ,furthest away from the acid, attempts are made to organise the exudate and granulation tissue forms, which then progresses to a collagenous scar.
In an established ulcer, these processes occur all at once (therefore is a chronic inflammatory process).

Question 28

What are Possible complications of chronic peptic ulcers?

Answer 28

Haemorrhage
Penetration
The Ulcer penetrates the full thickness of the stomach or duodenal wall and progresses into underlying local tissue  in particular the liver or pancreas.
Penetration of the pancreas manifests clinically as severe back pain.

Perforation
Which leads to peritonitis

Fibrous Stricture
Mostly seen in oesophageal peptic ulcers.
Fibrous thickening caused by healing leads to scarring of the eosophagus and obstruction

Question 29

The 4 main elements to optimal food absorption are?

Answer 29

1. The Pancreas:
   secretes digestive enzymes into the gut lumen which breakdown macromolecules
2. The Liver
   Secretes bile acids needed for solubilisation and absorption of fats
3. The Mucosa
   Specialised for absorption: including transverse mucosal fold and villi
4. Mucosal Enzymes
   Located on the brush border. These hydrolyse large molecules such as complex sugars (sucrase / lactase)

Question 30

What is celiac disease?

Answer 30

The important cause of small intestine malabsorption (in the developed world) is celiac disease.

Celiac Disease is caused by hypersensitivity to a component of gluten.
Autoimmune response to the protein gliadin (a component of gluten) which causes atrophy of small intestinal villi
Diagnosis made by biopsy of small bowel mucosa.
Histologically, the immune mediated damage causes heavy lymphocyte infiltration of lamina propria, significant loss of villous architecture.
A common cause of failure to thrive in infants and children.
Complete withdrawal of gliadin from the diet leads to gradual recovery of villus structure .

Question 31

What is Chronic Inflammatory Bowel Disease?

Answer 31

There are to main types of inflammatory bowel disease of no known cause (autoimmune):

Crohn’s Disease
Granulomatous inflammation of the bowel wall, most common in the terminal ileus.

Ulcerative Colitis
Chronic inflammatory disease of the rectal mucosa, which may extend to involve the whole of the colon.

Both types are associated with systemic manifestation outside of the intestine .

Question 32

What is chron’s disease?

Answer 32

Women > Men
Terminal Ileum most affected
Early stage of the disease shows marked swelling of the submucosa and mucosa
This leads to loss of normal pattern of transverse folds
Small focal haemorrhagic ulceration occurs which over time develop into fissures
In establish Crohn’s this is termed cobblestone pattern due to deep interconnecting fissures.
Strictures can cause obstruction.

Question 33

What is ulcerative collitis?

Answer 33

Affects the rectum and may extend into the colon (in extensive disease, it can affect the whole colon mucosa).
Patients develop diarrhoea: with the faeces being mixed with blood, mucus and pus.

There are 3 clinical patterns of the disease:
Active Acute – show areas of ulceration & inflammation in the mucosa & lamina propria
Chronic Quiescent – no prominent ulceration, mucosa appears red, granular and thinned – evidence of chronic inflammation
Fulminant active disease – extensive inflammation and ulceration

Stress is believe to exacerbate the disease in some people
10% of patients require surgery
10% have persistent active disease despite treatment
80% have chronic quiescent colitis with infrequent episodes of relapse.

Systemic Complications of Ulcerative Colitis:
Erythema Nodosum
Iritis
Arthropathy of large joints
Sacroiliitis
Ankylosing Spondylitis

Question 34

True or false? Vascular diseases of the intestines are most commonly seen in the elderly with severe atherosclerosis

Answer 34

True

Question 35

Arterial occlusion may be due to?

Answer 35

Emboli from intracardiac thrombosis
- thrombus formation following an MI or from mitral / atrial valve stents. The embolus can lodge in the superior mesenteric artery which supplies the entire small intestine.

Thrombosis in a severely atherosclerotic mesenteric artery

Venous infarction due to strangulation
-usually due to a strangulated bowel loop

Question 36

What is acute appendicitis?

Answer 36

common cause of abdominal pain
Can be caused by obstruction of the lumen of the appendix, usually by faeces

Complications of appendicitis include:
peritonitis and subsequent spread of infection
involvement of adjacent bowel loops causing perforation of small bowel