Figure 31. Prone RAO spot image from single-contrast esophagography shows beaklike narrowing (black arrows) of distal esophagus caused by secondary achalasia. Note greater length of narrowed segment than is usually seen in primary achalasia (see Fig 30). Also note metallic esophageal stent (white arrow) for palliation of esophageal carcinoma, which presumably had spread to gastroesophageal junction via periesophageal lymphatics. This image was obtained in an elderly patient with recent onset of dysphagia and weight loss.