Archived case 179 · May 28-June 4, 2015
Achalasia
Middle-aged patient with dysphagia
The question posed to readers
What are the pertinent imaging findings? What is your leading diagnosis? What would you consider doing next?
Images
Imaging findings
Radiologic Findings PA (Fig. 1A) and lateral (Fig. 1B) chest radiographs reveal a predominantly air-filled tubular structure projecting rightward and lateral to the tracheal air column and extending from the thoracic inlet to the subcarina. Below the carina, this assumes an hour-glass configuration and becomes a large ovoid retrocardiac opacity with a demonstrable air-fluid level that bulges both the right and left paraspinal line, obliterates the azygoesophageal recess and inferior hilar window, and exerts mass effect upon and displaces the lower lobe airways posteriorly. There is also anterior bowing and displacement of the tracheal air column on the lateral exam (Fig. 1B). Note the absence of gastric fundal air in the left upper quadrant but also the absence of mediastinal and or abdominal surgical clips or staples (Fig. 1A). The constellations of imaging findings confirm this is located in the middle mediastinal compartment and is an esophageal-based process. The next step in the evaluation may include esophagography, esophagoscopy, manometry or CT. Answer Diagnosis: Achalasia
Diagnosis
Achalasia
Answer
Diagnosis: Achalasia
Differential Diagnosis
· Obstructing Esophageal Cancer
· Distal Esophageal Stricture
· Various Esophageal Dysmotility Syndromes
· Chagas Disease
· Neoesophagus following Esophagectomy and Conduit Reconstruction
Discussion
Primary or idiopathic achalasia is a disease of the myenteric plexus (Auerbach plexus) of the esophagus in which peristalsis is markedly diminished or even absent. Secondary achalasia may simulate primary disease but is the result of underlying neoplasia.
Clinical Findings
Primary or idiopathic achalasia usually has its onset in early adulthood whereas secondary achalasia presents later in life. Presenting symptoms may include dysphagia, regurgitation, halitosis from stasis or esophageal secretions, aspiration pneumonia, and esophageal candidiasis. Long-standing disease may also be complicated by an increased incidence of squamous cell carcinoma of the distal esophagus.
Imaging Findings
Chest Radiography
· Air-filled or fluid-filled tubular structure in the mediastinum (Fig. 1A; 1B)
· Progressive esophageal dilatation and distention may obliterate normal mediastinal lines, stripes, and interfaces (e.g. azygos esophageal recess; inferior hilar window; retrocardiac clears space; retrotracheal triangle; etc.) (Fig. 1A; 1B)
· Small or absent gastric fundus air (Fig. 1A; 1B)
· Anterior displacement and bowing of tracheal air column (Fig. 1B)
· Foci or air space disease, consolidation, basilar bronchiectasis (e.g., aspiration pneumonia; recurrent bouts of aspiration)
Esophography
· Disordered peristalsis; early in disease
· Diminished or absent peristalsis; latter in disease
· Dilution of barium contrast by retained esophageal secretions
· Distended or dilated esophagus
· +/- Megaesophagus
· Distal esophagus demonstrates a smooth, tapered narrowing caused by the contracted esophageal sphincter (“bird-beak” or “rat-tail” sign)
· Gravity may partially overcome the decreased peristalsis and tightened sphincter allowing intermittent passage of small amounts of contrast media when patient is upright
· Little contrast passes through distal esophagus when patient is supine
CT
· Air and or fluid-filled dilated esophagus
· Retained secretions and or debris in the dilated esophagus
· Areas of dependent lung air-space disease manifest as ground-glass opacities and or frank consolidations
· Air-space consolidations may contain regions of fatty attenuation (e.g. lipoid pneumonia)
Treatment
· Pneumatic dilatation
· Surgical myotomy
Selected Readings
1. Hansell DM, Armstrong P, Lynch DA, et al. Mediastinal and Aortic Disease. In: Hansell DM, Armstrong P, Lynch DA, McAdams HP, eds. Imaging of Diseases of the Chest, 4th ed. Philadelphia: Elsevier Mosby; 2005: 901-1021.
2. Mueller CF, Klecker RJ, King MA. Case 3. Achalasia. AJR 2000; 175: 867; 870-871.
3. Parker MS, Rosado de-Christenson ML, Abbott GF. Achalasia. In: Chest Imaging Case Atlas, 2nd ed. New York: Thieme; 2012: 805-808.
4. Woodfield CA, Levine MS, Rubesin SE, Langlotz CP, Laufer I. Diagnosis of Primary versus Secondary Achalasia: Reassessment of Clinical and Radiographic Criteria. AJR 2000; 175: 727-731.Original case written by its authors at Virginia Commonwealth University and published at this address as part of a weekly teaching collection. Reproduced here as an archive.