Histo: Upper GI Disease Flashcards
(44 cards)
What is a key histological feature of the oesophageal mucosa?
Presence of submucosal glands
what is the Z-line?
The point in the oesophagus at which the epithelium transitions from being squamous to being columnar
What does the body and fundus of the stomach have in abundance?
Specialised glands responsible for producing acid and enzymes
Which part of the stomach tends to be affected by H. pylori-associated gastritis?
Pylorus and antrum
What are the three layers of the gastric mucosa?
- Columnar epithelium
- Lamina propria
- Muscularis mucosa
What is the normal villous: crypt ratio?
2:1
What does the presence of goblet cells in the stomach signify?
Intestinal metaplasia
NOTE: goblet cells are NOT normally seen in the stomach
What is the characteristic histological feature of acute oesophagitis?
Presence of lots of neutrophils
This is usually caused by GORD
What can acute oesophagitis result in?
- Ulceration
- Haemorrhage
- Perforate
- Fibrosis
- Stricture
- Barrett’s oesophagus
Define Barrett’s oesophagus.
Metaplastic process by which the normal sqaumous epithelium of the lower oesophagus is replaced by columnar epithlieum
NOTE: this is also known as columnar-lined epithelium (CLO)
What further degree of metaplasia is associated with an even greater risk of cancer than Barrett’s oesophagus?
Intestinal metaplasia - goblet cells become visible
NOTE: metaplasia is reversible
Outline the histological stages that occur leading up to Upper GI cancer
- Metaplasia (not considered pre-malignant as is reversible)
- Dysplasia (histological and cytological changes similiar to that of cancer but no invasion of basement membrane)
- Adenocarcinoma (invasion through basement membrane occurs)
The Upper GI pathway to cancer differs from the lower GI. Upper GI is referenced as flat pathway (metaplasia –> dysplasia –> cancer). While Lower GI is referred to as Polyp pathway as often there is formation of a polyp.
Define dysplasia.
Changes showing some of the cytological and histological features of malignancy but with no invasion through the basement membrane.
What is squamous carcinoma of the oesophagus associated with?
- Smoking and alcohol
- It tends to affect the upper/middle 2/3rds of the oesophagus
- It is the most common type of oesophageal cancer in Africa
What are the main histological features of squamous cell carcinoma of the oesophagus?
Cells produce keratin (normal oesophageal squamous epithelium is non-keratinised)
Intercellular bridges
What is adenocarcinoma of the oesophagus associated with
- Bottom 1/3rd
- Associations: GORD, Barrett’s oesophagus
What are the main histological features of adenocarcinoma of the oesophagus?
Histology:
- Glandular epithelium
- Mucin
How is eosinophilic oesophagitis treated?
- Steroids
- Allergen removal
NOTE: this is associated with an allergic reaction (asthma of the oesophagus). It is due to allergy to food causing muscle spasm and dysphagia.
What is the commonest cause of oesophageal varices?
- Cirrhosis of the liver (Most common)
- Portal vein thrombosis
Histological differences between Acute and Chronic Gastritis
Acute Gastritis = Neutrophil infiltration
Chronic Gastritis = Lymphocyte infiltration (may have some neutrophils due to co-existent acute changes)
Causes of Acute Gastritis
Chemical = Aspirin/NSAIDs, Alcohol, Corrosives
Bacterial = H. pylori, CMV
Causes of chronic gastritis
ABCD:
Autoimmune (atrophic) = i.e. antiparietal ABs
Bacteria (atrophic/non-atrophic) = H.pylori, CMV
Chemical = NSAIDs, bile reflux
D = IBD
What is mucosa-associated lymphoid tissue (MALT) and what is their presence indicative of?
- 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 (MALToma)
Name a key virulence factor that enables H. pylori to cause chronic infection.
Cag-A positive H. pylori has a needle-like appendage that injects toxins into intercellular junctions allowing bacteria to attach more easily