EUSからみた早期胃癌の深達度分類―潰瘍合併病変を中心に

Comparison of Classifications of the Depth of Early Gastric Cancer Invasion Estimated by EUS

要旨　早期胃癌の代表的なEUSによる深達度分類をUl(＋)病変を中心に比較検討した．m病変では，第3層が両側性に胃内腔側に向かって滑らかに先細り状に収束し，同部に扇状の低エコー域を認めることが基本である．若干のニュアンスの違いはあるが，各報告者間には一致点も多いと思われる．一方，sm癌では，先細りする第3層の先端に不整を認めるもの，弧状に中断するもの，第3層の低エコー域が境界不明瞭に中断するもの，胃内外に軽度壁肥厚を認めるものなどとそれぞれの分類が大きく異なっている．すなわち，Ul(＋)sm癌の診断基準を煮詰めることで，EUSによる深達度分類の統一が可能になるものと考えられた．

　Comparative study regarding with the classifications of depth of invasion of early gastric cancer associated with peptic ulcer or ulcer scar estimated by EUS was performed.

　In mucosal cancer, smooth tapering of the submucosal layer with fan-shaped hypoechoic area was the basic EUS finding. And it was widely accepted.

　In submucosal cancer, on the other hand, various criteria were proposed: irregularity of the tapered submucosal layer, arch shaped narrowing with or without fusion, obscure interruption of the submucosal layer, slight thickening of the gastric wall to inward and outward, etc. were regarded as the sign of submucosal cancer by EUS.

　The diagnostic criteria of the depth of invasion by EUS will be refined by standardization of diagnostic criteria of the submucosal cancer invasion.