十二指腸上皮性腫瘍における拡大内視鏡の応用と臨床的取り扱い

Magnifying Endoscopy with Narrow-band Imaging for Superficial Non-ampullary Duodenal Epithelial Tumors

要旨●十二指腸上皮性腫瘍は早期発見例が増加しているものの，その疾患頻度の低さから，標準的な診断や治療方針は確立されておらず，通常内視鏡検査だけでなく術前生検においても腺腫と粘膜内癌の鑑別診断は困難とされている．近年，NBIなどの画像強調観察や拡大内視鏡の発達により，その質的診断の有用性が報告されており，今後生検によらない術前内視鏡診断の向上が期待される．十二指腸においては，生検を行うことで容易に粘膜下層の線維化が生じ，内視鏡治療が困難となることがあり，術前の安易な生検は避けるべきである．また，生検による人工的変化が生じることで，拡大内視鏡所見に修飾が加わることがあることを留意する必要がある．

　Recent advancements in the endoscopic technology might increase the odds of detecting SNADET（superficial non-ampullary duodenal epithelial tumor）lesions. However, owing to the rarity of SNADET, endoscopic findings in SNADET have not yet been established. The accuracy of the duodenal biopsy sampling is relatively low, and a biopsy might cause inadvertent submucosal fibrosis and further complicate ER（endoscopic resection）. In addition, magnifying endoscopy with narrow-band imaging findings was possibly influenced by the biopsy procedure itself. Consequently, it is imperative to perform a biopsy while causing a minimal amount of damage. Hence, an endoscopy-based diagnosis is preferable for SNADETs that are likely to undergo ER. Newer endoscopic techniques, including magnifying endoscopy, could guide these diagnostics ; however, their additional advantages remain unclear, necessitating further investigation to elucidate these issues.