非乳頭部十二指腸腺腫・癌の拡大内視鏡診断—自施設での考え方

Magnified Endoscopic Diagnosis of Non-ampullary Duodenal Adenoma and Carcinoma

要旨●筆者らが表在型非乳頭部十二指腸上皮性腫瘍（SNADET）における腺腫と癌の内視鏡鑑別診断について検討した結果，癌と診断しうる病変は，①部位が十二指腸球部〜Vater乳頭より近位側の下行部，②腫瘍径が大きい，③表面構造closed-loop structureを呈する，④WOS陰性である傾向にあった．粘液形質との関連についての報告では，胃型形質が近位側十二指腸，特に球部に多く，隆起型を呈し，癌の割合が多かった．また腸型形質ではWOS陽性が多く，それぞれの粘液形質で異なる表面構造を呈した．現時点では，SNADETの内視鏡診断は表面構造ごとの分類や粘液形質を想定した診断を考慮するのが適切ではないかと考えている．

　We investigated the endoscopic differential diagnoses of adenoma and carcinoma in superficial non-ampullary duodenal epithelial tumor（SNADET）and observed that lesions, which could be diagnosed as carcinoma, were generally（1） located on the proximal side of the duodenum,（2） larger in diameter,（3） showed a closed-loop structure, and（4） negative for white opaque substance（WOS）. It has been reported that SNADETs with gastric phenotype that showed macroscopic type of tumor with protrusion and located on the proximal side of the duodenum centered on bulb to superior duodenal angle, was more likely to be diagnosed as cancer. It has also been reported that SNADETs with an intestinal phenotype tested positive for WOS. Moreover, each mucin phenotype had different surface structures. Presently, endoscopic diagnosis of SNADET can appropriately be interpreted based on surface structure and/or diagnosis assuming mucin phenotypes.