Question: A 31-year-old man was referred to our hospital for chest pain and dysphagia that had lasted for 3 months. He had no allergies and was not receiving any medication. Physical examination and laboratory tests did not show any specific findings. Although endoscopy showed no remarkable findings in the esophageal mucosa, the lumen was not extended enough even with adequate air supply (FigureA). Six biopsy samples were obtained at different regions of the esophagus, and no characteristic findings were noted in the epithelium.