The "bird beak" appearance is classic for primary achalasia, but secondary achalasia or "pseudoachalasia" should be considered in a patient with a suspicious clinical history ("pseudo-" because the tapering at the lower esophageal sphincter is not from a myenteric plexus abnormality, but instead from obstruction). Primary achalasia is unlikely to have a rapid onset in an elderly patient and one should look carefully to ensure that no mass is causing the findings.

In this particular case, the mass was a poorly differentiated adenocarcinoma at the gastro-esophageal junction.