Esophagus Flashcards
1
Q
Pharynx and Esophagus Anatomy
Nasopharynx, oropharynx, and hypopharynx?
Where is the cricopharyngeus muscle located?
What are the three anatomic rings of the distal esophagus?
A
- Pharynx
- Nasopharynx: Extends from the base of the skull to the soft palate.
- Oropharynx: Located behind the mouth and extends from the uvula to the hyoid bone.
- Hypopharynx: Extends from the hyoid bone to the cricopharyngeus muscle, which is located at the lower end of the cricoid cartilage.
- Esophagus
- The cricopharyngeus muscle, located at C5-6, is the upper esophageal sphincter and demarcates the transition between the pharynx superiorly and the cervical esophagus.
- The esophagus extends from the neck to the gastroesophageal junction. The distal esophagus passes through the diaphragmatic hiatus at approximately T10.
- The three anatomic rings of the distal esophagus are the A (muscular), B (mucosal), and C (diaphragmatic impression) rings.
2
Q
Esophageal Web
What is it?
Association?
A
- An esophageal web is a thin anterior infolding/indentation of the upper esophagus, which is usually asymptomatic but may be a cause of dysphagia. There is a controversial association with anemia (Plummer-Vinson syndrome) and upper esophageal carcinoma.
3
Q
Schatzki Ring
What is it?
What is the asymptomatic version called?
Which is more sensitive - upper GI or endoscopy?
A
- A Schatzki ring is a focal narrowing of the B (mucosal) ring of the distal esophagus, causing intermittent dysphagia.
- A true Schatzki ring requires clinical symptoms of dysphagia in addition to esophageal narrowing seen on imaging.
- Asymptomatic narrowing of the B ring is referred to as a lower esophageal ring.
- An upper GI study is more sensitive than endoscopy. The key imaging feature is focal circumferential constriction near the GE junction, almost always associated with a hiatal hernia.
- On an upper GI study, most symptomatic rings do not allow passage of a 12 mm tablet.
4
Q
DDx for circumferential esophageal contriction
A
- Focal stricture
- Muscular esophageal ring above the GE
- junction (also known as an A ring).
- Esophageal cancer
- Esophageal web (rarely circumferential, usually in cervical esophagus).
5
Q
Reflux (peptic) Esophagitis
What causes it? What does it lead to?
What etiologies are there?
What does it appear as?
Chronic esophagitis and scarring developing after prolonged exposure, which causes what?
A
- Reflux (peptic) esophagitis is caused by exposure of the esophageal mucosa to acidic gastric secretions, which leads to distal ulcerations and eventual stricture.
- Peptic esophagitis is most commonly caused by gastroesophageal reflux, but is also seen in:
- Zollinger-Ellison, due to increased acid production.
- Scleroderma, due to gastroesophageal sphincter fibrosis and resultant incompetence.
- Reflux esophagitis appears as thickened distal esophageal folds.
- Chronic esophagitis and scarring develop after prolonged exposure to acid, which causes a smoothly tapered stricture above the GE junction.
6
Q
Barrett Esophagus
What is it?
It is a precursor lesion to what?
Imaging?
What is it often associated with?
A
- An important long-term sequela of peptic esophagitis is Barrett esophagus, which is metaplasia of normal squamous epithelium to gastric-type adenomatous mucosa.
- Barrett esophagus is a precursor lesion to esophageal carcinoma.
- Nearly 10% of patients with reflux esophagitis may have some adenomatous metaplasia.
- On imaging, Barrett demonstrates a featureless distal esophagus, with signs of active reflux esophagitis (mucosal granularity and superficial erosions) more proximally.
- Barrett esophagus is often associated with esophageal stricture, which is abnormally high in location compared to a peptic stricture.
7
Q
Infectious Esophagitis
What is typically performed in medical practice?
What are the three etiologies? Characteristic features?
A
- Although the radiographic distinction between types of infections has been described, endoscopy and biopsy are typically performed in clinical practice.
- Esophageal candidiasis can present as a spectrum from scattered plaque-like lesions in mild disease to very shaggy esophagus in severe cases.
- Herpes esophagitis typically causes discrete small ulcerations scattered randomly throughout the esophagus.
- CMV/HIV esophagitis characteristically causes a large, flat, ovoid ulcer.
8
Q
Where in the esophagus does medication-induced esophagus occur?
A
- Medication-induced esophagitis typically causes an ulcer at the level of the aortic arch or distal esophagus, which are areas of relative narrowing that may predispose to temporary hold-ups in passage.
9
Q
Crohn Esophagitis
Occurrence rate?
Usually seen when?
What can happen to the aphthous ulcers?
A
- Crohn esophagitis is very rare and is usually seen in the setting of severe disease in the small bowel and colon.
- Aphthous ulcers (discrete ulcers surrounded by mounds of edema) may become confluent.
10
Q
Esophageal Strictures
A
11
Q
Esophageal Strictures
What kinds of strictures are there?
What could fibrosis of distal esophagus cause?
Locations of these strictures?
Specifics on caustic/NG tube strictures?
Specifics about radiation-induced strictures?
A
-
Peptic stricture: A peptic stricture is secondary to chronic reflux.
- Peptic strictures are located distally, usually just above the GE junction.
- A peptic stricture may be focal or involve a longer segment of esophagus. Fibrosis can cause esophageal shortening, leading to a hiatal hernia as the stomach is pulled into the thorax.
-
Barrett esophagus stricture: typically occurs in the mid-esophagus, above the metaplastic adenomatous transition.
- Barrett strictures occur higher than peptic strictures because adenomatous tissue is acid-resistant and therefore unaffected by gastric secretions.
- Malignant stricture (due to esophageal carcinoma): key imaging finding is shouldered margins, which suggests circumferential luminal narrowing by a mass.
-
Caustic stricture/nasogastric (NG) tube stricture: Both caustic strictures and strictures secondary to nasogastric tube placement are typically long, smooth, and narrow.
- Strictures develop 1-3 months after the caustic ingestion or NG tube placement.
- Caustic strictures are associated with an increased risk of cancer, with a long lag time of up to 20 years after the initial insult.
- Caustic strictures are usually longer than peptic strictures.
-
Radiation stricture: Radiation strictures are long, smooth and narrow, similar to caustic strictures. However, in contrast to strictures from an Ng tube, caustic ingestion, and reflux, radiation strictures usually spare the GE junction.
- It generally requires more than 50 gy of radiation to cause an esophageal stricture.
- Acute radiation esophagitis occurs 1-4 weeks after radiation therapy.
- Radiation strictures develop later, occurring 4-8 months after radiation.
- Extrinsic compression from mediastinal adenopathy: Cross-sectional imaging would best evaluate if extrinsic compression is suspected.
12
Q
What is the initial step in evaluating an esophageal mass?
A
- Masses arising from the mucosa, submucosa, and extrinsic to the esophagus produce characteristic effects on the esophagus, which are usually able to be seen on imaging.
13
Q
What are the benign esophageal masses?
A
- Mesenchymal tumor
- Adenoma
- Inflammatory polyp
- Fibrovascular polyp
- Varices
- Foregut duplication cyst
- Esophageal foreign body
14
Q
Benign Esophageal Masses
Mesenchymal tumor
What are they?
Most common types?
Barium swallow appearance?
A
- Benign mesenchymal tumors are the most common submucosal tumors and include gastrointestinal stromal tumor (GIST), leiomyoma, lipoma, hemangioma, and others.
- The classification varies in the literature, with both GIST and leiomyoma described as the most common.
- On a barium swallow, a mesenchymal tumor typically appears as smooth, round, submucosal filling defect.
15
Q
Benign Esophageal Masses
Adenoma
Inflammatory Polyp
Fibrovascular Polyp - Image characteristic?
A
- An esophageal adenoma is a benign mucosal lesion with malignant potential, usually arising within Barrett esophagus. Most are <1.5 cm in size and resected at endoscopy.
- An inflammatory polyp is a non-neoplastic, enlarged gastric fold that protrudes up into the lower esophagus. Inflammatory polyps are almost always associated with reflux and always contiguous with a gastric fold. They are mucosal in location.
- A fibrovascular polyp is a pedunculated mass composed of mesenchymal elements with a significant fatty component. In contrast to an esophageal adenoma, there is no malignant potential. Fibrovascular polyps usually occur in the cervical esophagus. The clinical presentation can be dramatic, with regurgitation of a fleshy mass. CT is usually diagnostic, demonstrating intra-lesional fatty component.
19
Q
Esophageal Carcinoma
Imaging appearence? How to differentiate the uncommon “varicoid” appearing esophageal CA with a varices?
What are the twp kinds of esophageal CA? Where in the esophagus do each of these occur usually? Risk factors?
A
- Esophageal carcinoma has a broad range of appearances. Early esophageal cancer may be apparent on barium swallow as a plaque-like lesion, polypoid lesion, or focal irregularity of the esophageal wall. A classic appearance of advanced esophageal carcinoma is a mass causing a stricture with a “shouldered” edge and irregular contour. The uncommon varicoid appearance can be initially confused with varices, but the tumor does not change shape with peristaltic waves as varices typically do.
- Esophageal carcinoma may be squamous cell carcinoma SCC or adenocarcinoma, which cannot be reliably differentiated on barium studies. SCC tends to involve the upper or mid-esophagus and adenocarcinoma typically involves the distal esophagus and may extend into the stomach.
- SCC is most commonly due to smoking and alcohol. Less common risk factors include celiac disease, Plummer-vinson, achalasia, and human papillomavirus (which more commonly causes laryngeal squamous cell carcinoma).
- Adenocarcinoma is due to chronic reflux, arising from Barrett’s esophagus distally. Its incidence has been rising in recent years.
23
Q
Achalasia
What is it? Why does it happen?
What is vigorous achalasia?
What is a secondary cause of achalasia?
Potential complications?
Classic imaging?
Treatment?
What is pseudoachalasia? How to differentiate?
A
- Achalasia is a motility disorder of the distal esophagus, which is unable to relax due to an abnormality of myenteric ganglia in the Auerbach plexus. Vigorous achalasia is a less severe form of achalasia consisting of repetitive nonpropulsive contractions.
- Chagas disease causes a secondary achalasia that is indistinguishable radiographically from primary achalasia.
- Potential complications of chronic achalasia include esophageal cancer, which has a lag period of at least 20 years, and candidal infection from stasis.
- The classic imaging appearance of achalasia is a massively dilated esophagus with a bird’s beak stricture near the gastroesophageal junction.
- Surgical treatment of achalasia is the Heller myotomy, which is an incision of the lower esophageal muscle fibers.
- Pseudoachalasia is caused by an obstructing gastroesophageal junction cancer. In achalasia, there is a transient relaxation of the stricture when the patient stands. In pseudoachalasia, however, the fixed obstruction does not relax with standing.
29
Q
Feline Esophagus
What is it?
Is there a controversial association?
A
- Feline esophagus is thought to be a normal variant characterized by multiple transverse esophageal folds.
- There is a controversial association with esophagitis, where the incidence of esophagitis may be increased in the presence of feline esophagus.
30
Q
Aberrant Right Subclavian Artery
Prevalence?
Where is it relative to esophagus?
Appearance on upper GI study?
A
- Aberrant right subclavian artery (with a normal left arch) is seen in approximately 1% of patients and is almost always asymptomatic.
- The aberrant right subclavian artery travels posterior to the esophagus, where it may rarely produce dysphagia.
- On an upper GI study, the resultant posterior esophageal indentation is always smooth.
