Clinicopathological Features and Magnifying Chromoendoscopic Findings of Non-Ampullary Duodenal Epithelial Tumors.

<bold><italic>Background and Aims:</italic></bold> We aimed to investigate an association between clinicopathological features, including immunohistochemical mucin phenotypes, and magnifying chromoendoscopic findings with crystal violet staining (ME-CV) in non-ampullary duodenal epithelial tumors (NADETs). <bold><italic>Methods:</italic></bold> A total of 55 patients with NADET were divided into 3 groups by mucin phenotype: intestinal, gastrointestinal, or gastric. ME-CV findings were classified into 4 patterns: convoluted, leaf-like, reticular/sulciolar, and pinecone. The clinicopathological features and ME-CV findings were compared among the mucin phenotypes. <bold><italic>Results:</italic></bold> Tumors of the gastric type were located in the duodenal bulb (<italic>p</italic> < 0.001), and contained pyloric gland adenoma (<italic>p</italic> < 0.001) more frequently than the other types. White-light endoscopy indicated that milk-white mucosa was less frequent in tumors of the gastric type than in those of the gastrointestinal type (<italic>p</italic> = 0.006) and the intestinal type (<italic>p</italic> < 0.001). ME-CV findings were significantly different between the gastric type and the other type (<italic>p</italic> = 0.028). Totally, 5 of 8 tumors of the gastric type manifested a pinecone pattern, 4 of which were compatible with pyloric gland adenoma. <bold><italic>Conclusions:</italic></bold> The endoscopic findings of NADETs differ according to mucin phenotype. A pinecone pattern under ME-CV may be characteristic of NADETs of the gastric type, especially pyloric gland adenoma. [ABSTRACT FROM AUTHOR]