OESOPHAGUS (Robbins pp 776)

There are a range of things that can go wrong with the oesophagus and these can be split into the following categories:

1. Congenital
   

   1. Atresia & Fistula: Atresia means that the oesophagus ends as a blind ended tube. Sometimes, either one of the blind tubes (upper/lower) can communicate with the tracheobronchial system ≫ fistula.

   2. Stenosis, webs, rings: The oesophagus has a submucosa full of connective tissue. If fibrosis occurs here, then the submucosa thickens and partly obstructs the lumen ≫stenosis. Fibrosis of submucosa occurs as a result of injury to oesophagus. Webs and rings are protrusions of the mucosa into the lumen, occurring semicircumferentially.

2. Functional
   

   1. Achalasia: This is when the LES is non-functional, causing a chronic dilatation above this point.

   2. Hiatus hernia: This is when the stomach protrudes into the thorax, because there is a gap between the diaphragm and oesophagus. Two types present:1) Sliding hernia (stomach as a whole enters above), 2) Paraoesophageal (part of stomach enters adjacent to the oesophagus).

   3. Diverticula: Outpouching of wall of oesophagus. Three types present: 1) Zenker, 2) Traction, 3) Epiphrenic.

   4. Mallory-Weiss (Laceration): This is a longitudinal tear at the gastrooesophageal junction. Occurs due to severe retching, coughing, gastric reflux.

   5. Varices: Due to portal hypertension, blood is redirected via oesophageal veins ≫ azygous veins ≫ systemic circ. Eventually will rupture and cause haemorrhage ≫ hematemesis.

3. Inflammatory

   1. Infections: Candida

   2. Chemical

   3. Reflux Oesophagitis: This occurs as a result of reflux of gastric juices into the lower oesophagus.

      1. Aetiology: 1) Failure of LES: pregnancy, alcohol, hypothyroidism etc, 2) Sliding hiatal hernia, 3) Delayed gastric emptying, 4) Oesophageal capacity to repair itself is lost.

      2. Macroscopy / Microscopy: 1) Presence of eosinophils, neutrophils, lymphocytes in EPITHELIAL LAYER, 2) Basal zone of epithelium is >20% of total thickeness, 3) papillae of lamina propria extends further into epithelium.

      3. Clinical features: Dysphagia, pain, heartburn, soar taste in mouth, rarely hematemesis.

      4. Complications: BARRETT OESOPHAGUS: as a response to prolonged injury, the stratified squamous epithelium is replaced by simple columnar epithelium (i.e.: metaplasia occurs). Barrett mucosa is associated with increased risk of adenocarcinoma of oesophagus.

4. Tumours

Category: Pathology Notes