Department of Gastroenterology;
Kitasato University East Hospital;
2-1-1 Asamizodai;
Minami-ku;
Sagamihara;
Kanagawa 252-0380;
Japan;
Department of Pathology;
Kitasato University East Hospital;
2-1-1 Asamizodai;
Minami-ku;
Sagamihara;
Kanagawa 252-0380;
Japan;
Duodenal; well-differentiated; endocrine; tumors; Endoscopic; resection; Surgical; operation;