0IIbに対する進展範囲度診断―通常内視鏡・境界不明瞭病変に対する拡大内視鏡の有用性と限界─フルズーム派の立場から

Usefulness of Magnifying Endoscopy with Narrow-band Imaging for Determining the Margins of Superficial Flat Type（0IIb）of Early Gastric Carcinomas

要旨　背景と目的：単独IIb・随伴IIbは，通常内視鏡による境界診断の限界であった．単独IIb・随伴IIbの境界診断における通常内視鏡の限界と，通常内視鏡限界例に対する拡大内視鏡の有用性と限界を求める．対象と方法：福岡大学筑紫病院でESDを施行された425病変を対象とし，以下の検討を行った．（1）通常内視鏡による境界明瞭病変と不明瞭病変の頻度とそれぞれの病変における単独IIbと随伴IIbの頻度，（2）通常内視鏡・不明瞭病変に対する拡大内視鏡による境界診断が可能であった病変と限界であった病変の頻度，および単独IIbと随伴IIbの頻度，（3）拡大観察・限界病変の組織学的特徴．成績：（1）通常内視鏡観察で境界不明瞭な早期胃癌は，約20％であり，単独IIbや随伴IIbは，通常内視鏡診断の限界であった．（2）拡大内視鏡は，通常内視鏡・境界不明瞭例に対し，単独IIb・随伴IIbの肉眼型にかかわらず，76％の病変に対して全周性に境界診断が可能であった．（3）拡大内視鏡診断の限界例の組織学的特徴は，未分化型癌，分化型癌の中では，中分化腺癌，超高分化腺癌であった．結論：分化型癌であれば，通常観察で境界不明瞭な単独IIbと随伴IIbに対し，拡大内視鏡による境界診断は有用であった．未分化型癌，一部の中分化腺癌・超高分化腺癌は，拡大内視鏡診断の限界であった．

　Background & aims : Superficial flat type（IIb）of early gastric carcinoma or accompanied IIb lesions are used to a limitation of diagnosis by standard endoscopy alone. We investigated usefulness of magnifying endoscopy（ME）with narrow-band imaging（NBI）for determining the margins of such flat carcinomas.　

　Materials and methods : Consecutive 425 early gastric carcinomas, which had been resected by ESD, were included to this study. We studied the following subjects.（1）The prevalence of the carcinomas according to the macroscopic types whose margins were clear vs. unclear by standard endoscopy alone.（2）The usefulness and limitations of ME with NBI for determining of the margins of the carcinomas according to the macroscopic types, which showed unclear margins by standard endoscopy.（3）Histological characteristic for limitations of ME with NBI.

　Results :（1）Overall, the prevalence of the lesions, which showed unclear margins by standard endoscopy, was nearly 20％. IIb and accompanied IIb lesions were still limitations of standard endoscopy.（2）For 76％ of such leisions, ME with NBI was useful for determining the margins of the carcinoma irrespective of macroscopic type such as IIb.（3）The histological characteristic for the difficult lesions were mainly poorly differentiated adenocarcinoma and partly moderately- or very well-differentiated adenocarcinoma.

　Conclusions : ME with NBI enables endoscopist to determine the margins of carcinoma even in IIb or accompanied IIb lesions.