早期十二指腸腫瘍の内視鏡診断

Endoscopic Diagnosis of Duodenal Adenoma and Early Cancers

要旨●十二指腸腫瘍性病変はまれな疾患であるため，十二指腸腺腫と早期癌との鑑別診断に関する知見は少ない．当院で経験した症例と既報を合わせた37例の内視鏡的所見を検討した．通常内視鏡観察による腺腫の特徴は，平坦〜隆起型の表面粘膜は微細顆粒構造を呈し，易出血性を伴う点であった．一方，癌では，結節状の表面構造を有した隆起性病変で，絨毛の白色化の分布が縮小化する点が特徴的であった．拡大内視鏡観察では，表面微細構造による鑑別は困難であるが，微小血管の不整像が癌に認められ，有効な鑑別手段であると言える．しかし，NBI拡大内視鏡観察に関する報告は少なく，現時点で両者を鑑別する手段はないため，さらなる知見の集積が必要である．

　Due to the rarity of duodenal neoplastic lesions, there is little knowledge about the differential diagnosis between duodenal adenoma and early cancer. We examined 37 endoscopic findings that matched a previous report with the case that I experienced in Toyama University Hospital. Duodenal adenomas visualized using conventional endoscopy are characteristically flat, elevated lesions that present with a granule structure on the tumor surface. On the other hand, a cancerous tumor appears as a reddish, tuberous lesion. Using narrow-band imaging magnified endoscopy, it was difficult to distinguish an adenoma from a cancer according to the micro-surface pattern. Mucosal cancers can be effectively differentiated using the identification of irregular microvascular patterns. However, accumulation of further data is necessary because there are few case reports that used narrow-band imaging magnified endoscopic observation for adenoma and cancer differentiation.