未分化型癌：印環細胞癌—H. pylori未感染例と現感染例・除菌例の比較

The Endoscopic and Pathological Characteristics of Helicobacter pylori Uninfected Signet Ring Cell Carcinoma（Including Difference of Helicobacter pylori Present Infected and Eradicated Patients）

要旨●H. pylori未感染印環細胞癌の内視鏡的，病理組織学的特徴は明らかではない．今回，H. pylori現感染例とH. pylori除菌例との違いも含めて明らかにすべく検討を行った．対象は2010年1月〜2014年12月に，内視鏡的粘膜下層剝離術（ESD）を施行した印環細胞癌53例53病変（H. pylori現感染例19例，H. pylori除菌例14例，H. pylori未感染例20例）．方法は範囲診断を含めた内視鏡的特徴，病理組織学的特徴の比較を行った．その結果，H. pylori未感染例は内視鏡的特徴として現感染例・除菌例と比較して0-IIb型が多く，NBI併用拡大観察では現感染例と比較して窩間部開大所見が多く，範囲診断正診割合が高かった．また，病理組織学的特徴としては現感染例と比較して腫瘍径が小さかった．これらを念頭に置き，内視鏡検査を行うことが，H. pylori未感染印環細胞癌の診断において重要である．

　The endoscopic and pathological characteristics of HP（Helicobacter pylori）-uninfected signet ring cell carcinoma are not well-established. Therefore, in the present study, we elucidate the characteristics ; including difference between HP infected and eradicated patients.

　This study included a total of 53 lesions from 53 patients who underwent endoscopic submucosal dissection between January 2010 and December 2014. Of these, 19 lesions were in HP-infected patients, 14 were in HP-eradicated patients, and 20 were in HP-uninfected patients. We compared the endoscopic（including diagnostic demarcation）and pathological characteristics of lesions from these three groups.

　Endoscopic examination of lesions in HP-uninfected patients revealed macroscopic type 0-IIb lesions. In addition, findings of magnifying endoscopy with narrow-band imaging revealed an extended intervening part, and the accuracy of diagnostic demarcation was significantly high. Moreover, pathological examination revealed a small tumor diameter. Considering these characteristics, it is important to perform routine endoscopic examination for the diagnosis of HP-uninfected patients.