Department of Gastrointestinal Surgery;
Tokyo Medical and Dental University;
Tokyo;
Japan;
Department of Head and Neck Surgery;
Tokyo Medical and Dental University;
Tokyo;
Japan;
Department of Human Pathology;
Tokyo Medical and Dental University;
Tokyo;
Japan;
Endoscopic; Laryngopharyngeal; Surgery; Hypopharyngeal; Cancer; Multiple; Primary; Cancer; Trumpet; Maneuver; Endoscopic; Submucosal; Dissection;