AIM: To investigate the accuracy of endoscopic or biopsy diagnoses of superficial nonampullary duodenal epithelial tumors(NADETs).METHODS:Clinicopathological data were reviewed for84 superficial NADETs from 74 patients who underwent surgery or endoscopic resection between September2002 and August 2014 at a single prefectural cancer center.Superficial NADETs were defined as lesions confined to the mucosa or submucosa.Demographic and clinicopathological data were retrieved from charts,endoscopic and pathologic reports.Endoscopic reports included endoscopic diagnosis,location,gross type,diameter,color,and presence or absence of biopsy.Endoscopic diagnoses were made by an endoscopist in charge of the examination before biopsy specimens were obtained.Endoscopic images were obtained using routine,front-view,high-resolution video endoscopy,and chromoendoscopy with indigocarmine was performed for all lesions.Endoscopic images were reviewed by at least two endoscopists to assess endoscopic findings indicative of carcinoma.Preoperative diagnoses based on endoscopy and biopsy findings were compared with histological diagnoses of resected specimens.Sensitivity,specificity,and accuracy were assessed for endoscopic diagnosis and biopsy diagnosis.RESULTS:The majority(81%)of the lesions were located in the second portion of the duodenum.The median lesion diameter was 14.5 mm according to final histology.Surgery was performed for 49 lesions from 39 patients,and 35 lesions from 35 patients were endoscopically resected.Final histology confirmed 65carcinomas,15 adenomas,and 3 hyperplasias.A finaldiagnosis of duodenal carcinoma was made for 91%(52/57)of the lesions diagnosed as carcinoma by endoscopy and 93%(42/45)of the lesions diagnosed as carcinoma by biopsy.The sensitivity,specificity,and accuracy of endoscopic diagnoses were 80%,72%,and 78%,respectively,whereas those of biopsy diagnoses were 72%,80%,and 74%,respectively.Preoperative diagnoses of carcinomas were made in88%(57/65)of the carcinoma lesions via endoscopy or biopsy.Endoscopic findings associated with carcinoma were red color,depression,and mixed-type morphology.CONCLUSION:Preoperative endoscopy and biopsy showed similar accuracies in the diagnosis of carcinoma in patients with superficial NADETs. AIM: To investigate the accuracy of endoscopic or biopsy diagnoses of superficial nonampullary duodenal epithelial tumors (NADETs). METHODS: Clinicopathological data were reviewed for 84 superficial NADETs from 74 patients who underwent surgery or endoscopic resection between September2002 and August 2014 at a single prefectural cancer center . Superficial NADETs were defined as lesions confined to the mucosa or submucosa. Demographic and clinicopathological data were retrieved from charts, endoscopic and pathologic reports. Endoscopic reports included endoscopic diagnosis, location, gross type, diameter, color, and presence or absence of biopsy. Endoscopic diagnoses were made by an endoscopist in charge of the examination before biopsy specimens were obtained. Endoscopic images were obtained using routine, front-view, high-resolution video endoscopy, and chromoendoscopy with indigocarmine was performed for all lesions. Endoscopic images were reviewed by at least two endoscopists to assess endoscopic find ings indicative of carcinoma. Preoperative diagnoses based on endoscopy and biopsy findings were compared with histological diagnoses of resected specimens. Sensitivity, specificity, and accuracy were assessed for endoscopic diagnosis and biopsy diagnosis. RESULTS: The majority (81%) of the lesions were located in the second portion of the duodenum. The median lesion diameter was 14.5 mm according to final histology. The cerebrum was performed for 49 lesions from 39 patients, and 35 lesions from 35 patients were endoscopically resected. Final histology confirmed 65 carcinomas, 15 adenomas, and 3 hyperplasias. A final diagnosis of duodenal carcinoma was made for 91% (52/57) of the lesions diagnosed as carcinoma by endoscopy and 93% (42/45) of the lesions diagnosed as carcinoma by biopsy.The sensitivity, specificity, and accuracy of endoscopic diagnoses were 80%, 72%, and 78%, respectively, those of biopsy diagnoses were 72%, 80%, and 74%, respectively. Preoperative diagnoses of carcinomas were made in 88% (57/65) ofthe carcinoma lesions via endoscopy or biopsy. Endoscopic findings associated with carcinoma were red color, depression, and mixed-type morphology. CONCLUSION: Preoperative endoscopy and biopsy showed similar accuracies in the diagnosis of carcinoma in patients with superficial NADETs.