3. Esophagus Flashcards
Disorders in the Esophagus
- Congenital anomalies
- Esophageal agenesis
- Esophageal atresia - Esophagitis
- Laceration & Ruptures
- Chemical & Infectious esophagitis
- Reflux esophagitis (GERD) - Barrett Esophagus
- Esophageal obstruction
- Diffuse esophageal spasm
- Esophageal stenosis
- Esophageal mucosal webs
- Esophageal rings (Schatzki Rings)
- Achalasia - Neoplasm
- Squamous cell carcinoma
- Adenocarcinoma
Esophageal agenesis
Complete absence of the esophagus
Esophageal atresia
- Thin non-canalized cord replaces a segment of the
esophagus, causing esophageal obstruction - Occurs most commonly at or near to the bifurcation of the trachea
- Usually associated with a tracheoesophageal fistula
connecting the upper esophageal pouch to the trachea or the lower esophageal pouch to a bronchus
Definition of esophagitis
Inflammation of the esophageal mucosa
Laceration and ruptures leading to esophagitis
- Mallory-Weiss Tears
- Longitudinal tears in the esophagus near the gastroesophageal junction
- Often associated with severe retching or vomiting secondary to acute alcohol intoxication
- Postulated to be due to failure of normal reflex relaxation of the gastroesophageal musculature preceding antiperistaltic contractile waves in prolonged vomiting, resulting in stretching & tearing of the esophageal wall
- Presents with upper GI bleeding (hematemesis) - Boerhaave Syndrome
- Distal esophageal rupture due to vomiting
Chemical esophagitis
Esophageal mucosal damage by chemical irritants:
- Alcohol, corrosive acids/alkalis, excessively hot liquids, heavy smoking
- Chemotherapy & radiation
- Uremia
Infectious esophagitis
Esophageal mucosal damage by infectious agents:
- HSV, CMV, Candida
- Typically occurs in immunocompromised patients
Pathological effects & complications of Chemical & Infectious Esophagitis
- Dysphagia
- Hemorrhage
- Stricture
- Perforation
Definition of reflux esophagitis (Gastroesophageal Reflux Disease)
Reflux of acidic gastric contents into the lower esophagus resulting in acid-induced mucosal damage
- Due to decreased lower esophageal sphincter (LES) tone &/or increased abdominal pressure
Causes of reflux esophagitis
- Hiatal hernia (functional decrease in LES tone)
- Alcohol & tobacco use, pregnancy, antidepressants,
obesity (decrease LES tone) - Delayed gastric emptying (increases abdominal
pressure)
Pathological effects & complications of reflux esophagitis (GERD)
- Retrosternal pain (heartburn)
- Dysphagia (sclerosis & stricture)
- Peptic ulceration of esophageal mucosa with resultant hematemesis
- Intestinal metaplasia leading to Barrett esophagus with increased risk of adenocarcinoma
Definition of Barrett Esophagus
Complication of chronic GERD (10%), characterized by intestinal metaplasia within the esophageal squamous mucosa
Causes of Barrett esophagus
Chronic gastroesophageal reflux disease (i.e. anything
that causes prolonged reflux esophagitis)
Criteria for the diagnosis of Barrett esophagus
- Endoscopic evidence of columnar epithelium above
gastroesophageal junction - Histologic evidence of intestinal metaplasia (presence of goblet cells)
Morphology of Barrett esophagus
- [Grossly]
- Occurs in distal esophagus
- Red velvety mucosa amidst pearly grey- white appearance of normal squamous epithelium - [Histologically]
- Squamous epithelium replaced by metaplastic intestinal epithelium
Pathological Effects & Complications of Barrett esophagus
- Ulceration of esophageal mucosa & resultant bleeding
- Scarring & strictures
- Dysplasia
- Esophageal adenocarcinoma (40x risk)
Diffuse esophageal spasm
Causes increase in esophageal wall stress, resulting in the formation of small diverticulae (pseudodiverticulae as they lack a true muscularis)
- Zenker diverticulum (immediately above UES)
- Traction diverticulum (midpoint of esophagus)
- Epiphrenic diverticulum (immediately above LES)
Esophageal stenosis
- Due to fibrous thickening of the submucosa
- Causes:
- Congenital
- Acquired: chronic GERD, chemical and radiation-induced esophagitis
Esophageal mucosal webs
- Ledge-like, semicircumferential protrusions of mucosa most commonly found in the upper esophagus
- Unknown cause, but associated with GERD & chronic graft-versus-host disease
Esophageal rings (Schatzki rings)
Similar to esophageal mucosal webs but are circumferential & thicker, including submucosa &, in some cases, hypertrophic muscularis propria
Achalasia
Characterised by the triad of:
- Incomplete LES relaxation
- Increased LES tone
- Aperistalsis of the esophagus
Causes of achalasia
- Primary achalasia: idiopathic (failure of distal esophageal inhibitory neurons)
- Secondary achalasia: Chagas disease, diabetic
autonomic neuropathy, lesions of dorsal motor nuclei (due to polio or surgical ablation)
Epidemiology and associations of squamous cell carcinoma
- Older age group
- Males > females
- China, africa
- Dietary & environmental factors: alcohol, tobacco, nitrites, nitrosamines
Squamous cell carcinoma is typically found in
Middle portion of the esophagus
Pathogenesis of squamous cell carcinoma
- Carcinoma-in-situ to invasive squamous cell carcinoma progression
- Plentiful submucosal lymphatics present in esophageal wall, which permits tumour cell infiltration above & below level of apparent tumour (hence surgical resection of tumour may not clear all tumour cells)
- Local extension into mediastinum (direct invasion)
- Lymph node metastases: upper 1/3 (to cervical nodes), middle 1/3 (to mediastinal nodes), lower 1/3
(to gastric & celiac nodes)
Complications and pathological effects of squamous cell carcinoma
- Dysphagia, odynophagia
- Invasion of surrounding structures (pericardium, respiratory tree)
- Potentially forms tracheoesophageal fistula with subsequent aspiration
Epidemiology and associations of adenocarcinoma
- Males > Females
- Associated with Barrett esophagus (40x risk)
- Dietary & environmental factors: tobacco, obesity, prior radiation therapy
Adenocarcinoma is typically found in the
Distal esophagus (lower 1/3 of the esophagus)
Pathogenesis of adenocarcinoma
- Typically arises in a background of Barrett esophagus & chronic GERD
- Intestinal metaplasia → dysplasia → invasive adenocarcinoma progression
