Endoscopic diagnosis of superficial non-ampullary duodenal epithelial tumors in Japan: Multicenter case series

Background and Aim To verify the current status in Japan on endoscopic diagnosis of superficial non‐ampullary duodenal epithelial tumors (SNADET) by a multicenter case series through a questionnaire survey. Methods Nine endoscopists and a surgeon responded to a questionnaire on endoscopic diagnosis of SNADET. The subjects of this survey were histologically confirmed SNADET that were endoscopically or surgically resected from 2007 to 2012. This survey collected data of 364 patients with 396 SNADET. Results Of the 396 SNADET, 121 were histologically diagnosed as low‐grade dysplasia (LGD), 112 as high‐grade dysplasia (HGD), and 163 as superficial adenocarcinoma (SAC) including 153 mucosal carcinomas and 10 submucosal carcinomas. Total number of SNADET increased from 125 in the first half to 271 in the second half of the survey period. Compared to LGD, a significantly greater number of HGD or SAC was found in the tumors having a diameter >5 mm as well as solitary or predominantly red color. Preoperative endoscopic diagnosis indicated significantly higher sensitivity and accuracy and significantly lower specificity for HGD or SAC of final histology than preoperative biopsy. Ten submucosal carcinomas had 0‐I or 0‐IIa+IIc macroscopic‐type tumors with red color. Conclusions This multicenter case series study suggested that the number of resected SNADET is dramatically increasing in Japan. Tumor diameter >5 mm and red color seemed to be signs for tumors of HGD or SAC. Preoperative endoscopy may provide a more reliable diagnosis of final histology of HGD or SAC than preoperative biopsy. Further studies are warranted for establishing endoscopic features of submucosal carcinoma.