<prompt> A 40-year-old woman treated for many years for gastroesophageal reflux develops dysphagia and weight loss. Previous esophagoscopy has revealed cellular atypia. An esophagoscopy is about to be performed. What is it most likely to reveal?Leiomyoma arising from the long esophageal muscular layerSquamous cell carcinoma arising from esophageal mucosal liningAdenocarcinoma originated from islands of Barretts esophagusAdenocarcinoma extending from the stomach  <response>: Adenocarcinoma, originated from islands of Barretts esophagus, is today the most common cancer of the esophagus in the United States. 