Cervical dysphagia: pharyngeal protrusions and achalasia.

Cervical achalasia, webs, and pharyngeal protrusions, particularly Zenker's diverticula, are prominent sources of upper alimentary tract dysphagia. Since achalasia and webs can secondarily cause pharyngeal protrusions, they may coexist, and must be ruled out before commencing treatment. The nature and origin of these entities and means of radiographic distinction are discussed. Emphasis is placed on the various forms of lateral pharyngeal protrusion, which are the most poorly understood.