Achalasia is an esophageal motility disorder due to a failure of relaxation of the lower esophageal sphincter. This occurs due to an abnormality within the Auerbach plexus - be it primary or secondary.

Barium swallow demonstrates:

1. beaked tapering of the esophagus at the gastro-esophageal junction
2. a grossly dilated esophagus
3. tertiary contractions
4. air-fluid level on the control/plain film

Key Points:

1. achalasia is associated with an increased risk of esophageal malignancy
2. beware of pseudoachalasia due to the destruction of the plexus by a tumor such as linitis plastica
3. the radiologist has a role in treatment by balloon dilatation

Image courtesy of Dr Ian Bickle