Findings: PA radiograph (A) is unremarkable. The lateral view shows a slight anterior bowing of the trachea (B, arrow) with an apparently dilated upper esophagus with an air/solid interface (B, red arrow).

These findings are well seen in the cone down view, which better shows a thickened retrotracheal stripe (C, red arrows), a sign that suggests esophageal pathology, among others.
For all of you who diagnosed achalasia there is a negative finding: the lack of occupation of the retrocardiac space (D, circle) which practically rules out dilatation of the lower esophagus.

Sorry to say that I do not have additional images. After receiving the possible diagnosis of esophageal tumor, the patient went to another hospital, where esophagoscopy and biopsy confirmed upper esophageal dilatation by a carcinoma of the middle third.
 
Final diagnosis: Carcinoma of the middle third of the esophagus with proximal dilatation and food retention.
 
Congratulations to Dr Ahmad who was the first to describe the findings.
 
Teaching point: this case emphasizes the value of clinical information in selected cases. I suspect that some of you would not have discovered the dilated esophagus in the lateral view if I had withheld the history of dysphagia :).