Public Library Science Acta Medica Okayama 1932-6203 16 8 2021 Clinical and phenotypical characteristics of submucosal invasive carcinoma in non-ampullary duodenal cancer e0256797 EN Katsunori Matsueda Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Hiromitsu Kanzaki Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Ryuta Takenaka Department of Internal Medicine, Tsuyama Chuo Hospital Masahiro Nakagawa Department of Endoscopy, Hiroshima City Hiroshima Citizens Hospital Kazuhiro Matsueda Department of Gastroenterology and Hepatology, Kurashiki Central Hospital Masaya Iwamuro Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Seiji Kawano Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yoshiro Kawahara Department of Practical Gastrointestinal Endoscopy, Okayama University Hospital Tomohiro Toji Department of Diagnostic Pathology, Okayama University Hospital Takehiro Tanaka Department of Pathology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Takahito Yagi Department of Hepato-Biliary-Pancreatic Surgery, Okayama University Hospital Toshiyoshi Fujiwara Department of Gastroenterological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Hiroyuki Okada Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Objective The rare incidence of submucosal invasive non-ampullary duodenal carcinoma has led to scant information in literature; therefore, we compared the clinicopathological features between submucosal invasive carcinoma (SM-Ca), mucosal carcinoma (M-Ca), and advanced carcinoma (Ad-Ca). Materials We retrospectively analyzed 165 patients with sporadic non-ampullary duodenal carcinomas (SNADCs) from four institutions between January 2003 and December 2018. The SNADCs were divided to three groups according to histological diagnosis: SM-Ca, M-Ca, and Ad-Ca. The clinicopathological characteristics and mucin phenotypes were compared between groups. Results Among the 165 SNADCs, 11 (7%) were classified as SM-Ca, 70 (42%) as M-Ca, and 84 (51%) as Ad-Ca. We found that all SM-Ca (P = 0.013) and most Ad-Ca (P = 0.020) lesions were located on the oral-Vater; however, an almost equal distribution of M-Ca lesions was found between the oral- and anal-Vater. No significant difference was observed between the tumor diameter of M-Ca and SM-Ca; however, 45% (5/11) of SM-Ca were <= 10 mm. A total of 73% (8/11) of SM-Ca were classified as gastric phenotype and no lesions were classified as intestinal phenotype; whereas most M-Ca were classified as intestinal phenotype (67%, 8/12). Conclusions SM-Ca lesions were all located on the oral-Vater and were highly associated with the gastric mucin phenotype, which were different from the features of most M-Ca. No potential conflict of interest relevant to this article was reported.