3. Esophagus

Question 1

Disorders in the Esophagus

Answer 1

1. Congenital anomalies
   - Esophageal agenesis
   - Esophageal atresia
2. Esophagitis
   - Laceration & Ruptures
   - Chemical & Infectious esophagitis
   - Reflux esophagitis (GERD)
3. Barrett Esophagus
4. Esophageal obstruction
   - Diffuse esophageal spasm
   - Esophageal stenosis
   - Esophageal mucosal webs
   - Esophageal rings (Schatzki Rings)
   - Achalasia
5. Neoplasm
   - Squamous cell carcinoma
   - Adenocarcinoma

Question 2

Esophageal agenesis

Answer 2

Complete absence of the esophagus

Question 3

Esophageal atresia

Answer 3

1. Thin non-canalized cord replaces a segment of the
   esophagus, causing esophageal obstruction
2. Occurs most commonly at or near to the bifurcation of the trachea
3. Usually associated with a tracheoesophageal fistula
   connecting the upper esophageal pouch to the trachea or the lower esophageal pouch to a bronchus

Question 4

Definition of esophagitis

Answer 4

Inflammation of the esophageal mucosa

Question 5

Laceration and ruptures leading to esophagitis

Answer 5

1. 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)
2. Boerhaave Syndrome
   - Distal esophageal rupture due to vomiting

Question 6

Chemical esophagitis

Answer 6

Esophageal mucosal damage by chemical irritants:

• Alcohol, corrosive acids/alkalis, excessively hot liquids, heavy smoking
• Chemotherapy & radiation
• Uremia

Question 7

Infectious esophagitis

Answer 7

Esophageal mucosal damage by infectious agents:

1. HSV, CMV, Candida
2. Typically occurs in immunocompromised patients

Question 8

Pathological effects & complications of Chemical & Infectious Esophagitis

Answer 8

1. Dysphagia
2. Hemorrhage
3. Stricture
4. Perforation

Question 9

Definition of reflux esophagitis (Gastroesophageal Reflux Disease)

Answer 9

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

Question 10

Causes of reflux esophagitis

Answer 10

1. Hiatal hernia (functional decrease in LES tone)
2. Alcohol & tobacco use, pregnancy, antidepressants,
   obesity (decrease LES tone)
3. Delayed gastric emptying (increases abdominal
   pressure)

Question 11

Pathological effects & complications of reflux esophagitis (GERD)

Answer 11

1. Retrosternal pain (heartburn)
2. Dysphagia (sclerosis & stricture)
3. Peptic ulceration of esophageal mucosa with resultant hematemesis
4. Intestinal metaplasia leading to Barrett esophagus with increased risk of adenocarcinoma

Question 12

Definition of Barrett Esophagus

Answer 12

Complication of chronic GERD (10%), characterized by intestinal metaplasia within the esophageal squamous mucosa

Question 13

Causes of Barrett esophagus

Answer 13

Chronic gastroesophageal reflux disease (i.e. anything

that causes prolonged reflux esophagitis)

Question 14

Criteria for the diagnosis of Barrett esophagus

Answer 14

1. Endoscopic evidence of columnar epithelium above
   gastroesophageal junction
2. Histologic evidence of intestinal metaplasia (presence of goblet cells)

Question 15

Morphology of Barrett esophagus

Answer 15

1. [Grossly]
   - Occurs in distal esophagus
   - Red velvety mucosa amidst pearly grey- white appearance of normal squamous epithelium
2. [Histologically]
   - Squamous epithelium replaced by metaplastic intestinal epithelium

Question 16

Pathological Effects & Complications of Barrett esophagus

Answer 16

1. Ulceration of esophageal mucosa & resultant bleeding
2. Scarring & strictures
3. Dysplasia
4. Esophageal adenocarcinoma (40x risk)

Question 17

Diffuse esophageal spasm

Answer 17

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)

Question 18

Esophageal stenosis

Answer 18

1. Due to fibrous thickening of the submucosa
2. Causes:
   - Congenital
   - Acquired: chronic GERD, chemical and radiation-induced esophagitis

Question 19

Esophageal mucosal webs

Answer 19

1. Ledge-like, semicircumferential protrusions of mucosa most commonly found in the upper esophagus
2. Unknown cause, but associated with GERD & chronic graft-versus-host disease

Question 20

Esophageal rings (Schatzki rings)

Answer 20

Similar to esophageal mucosal webs but are circumferential & thicker, including submucosa &, in some cases, hypertrophic muscularis propria

Question 21

Achalasia

Answer 21

Characterised by the triad of:

1. Incomplete LES relaxation
2. Increased LES tone
3. Aperistalsis of the esophagus

Question 22

Causes of achalasia

Answer 22

1. Primary achalasia: idiopathic (failure of distal esophageal inhibitory neurons)
2. Secondary achalasia: Chagas disease, diabetic
   autonomic neuropathy, lesions of dorsal motor nuclei (due to polio or surgical ablation)

Question 23

Epidemiology and associations of squamous cell carcinoma

Answer 23

1. Older age group
2. Males > females
3. China, africa
4. Dietary & environmental factors: alcohol, tobacco, nitrites, nitrosamines

Question 24

Squamous cell carcinoma is typically found in

Answer 24

Middle portion of the esophagus

Question 25

Pathogenesis of squamous cell carcinoma

Answer 25

1. Carcinoma-in-situ to invasive squamous cell carcinoma progression 2. 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) 3. Local extension into mediastinum (direct invasion) 4. Lymph node metastases: upper 1/3 (to cervical nodes), middle 1/3 (to mediastinal nodes), lower 1/3 (to gastric & celiac nodes)

Question 26

Complications and pathological effects of squamous cell carcinoma

Answer 26

1. Dysphagia, odynophagia 2. Invasion of surrounding structures (pericardium, respiratory tree) 3. Potentially forms tracheoesophageal fistula with subsequent aspiration

Question 27

Epidemiology and associations of adenocarcinoma

Answer 27

1. Males > Females 2. Associated with Barrett esophagus (40x risk) 3. Dietary & environmental factors: tobacco, obesity, prior radiation therapy

Question 28

Adenocarcinoma is typically found in the

Answer 28

Distal esophagus (lower 1/3 of the esophagus)

Question 29

Pathogenesis of adenocarcinoma

Answer 29

1. Typically arises in a background of Barrett esophagus & chronic GERD 2. Intestinal metaplasia → dysplasia → invasive adenocarcinoma progression