2) Vater乳頭部の拡大観察と良悪性診断

Clinical Impact of Magnifying Endoscopy with Narrow Band Imaging for Ampullary Tumors

要旨　近年，narrow band imaging（NBI）併用拡大内視鏡の開発によって，消化管粘膜の微小表面構造および微小血管の観察が可能となった．Vater乳頭部の腺腫と腺癌の鑑別において粘膜表面の無構造域や屈曲，拡張，口径不同を伴う異常血管の出現が腺癌に多く認められた．特に異常血管の存在を腺癌と定義した場合のVater乳頭部腺癌を検出する感度，特異度は内視鏡下生検で50％，100％，NBI併用拡大内視鏡で83.4％，100％であった．NBI併用拡大内視鏡は生検では診断困難な腺腫内癌を検出しうる可能性がある．

　Recently, magnifying endoscopy with narrow band imaging (NBI) has been developed and could yield clear images of mucosal and microvascular structure. Regarding ampullary tumor, non-structural mucosa and abnormal vessels were able to be seen more often in adenocarcinoma. Sensitivity and specificity of forceps biopsy and magnifying endoscopy with NBI to differentiate adenocarcinoma from adenoma by the presence or absence of abnormal vessels were50％, 100％ and83.4％, 100％, respectively. The NBI system shows great potential to enable accurate diagnosis even of the foci of adenocarcinoma, which foci cannot be detected using forceps biopsy.