粘膜下腫瘍様食道癌と粘膜下腫瘍の鑑別—1/9層の有無に注目して

Distinguish between Submucosal like Esophageal Cancer and Submucosal Tumor by EUS

要旨●食道の平滑筋腫や顆粒細胞腫を中心とする間葉系腫瘍は粘膜下腫瘍（SMT）様の形態を示す．一方，食道癌にもSMT様の形態を示すものがあり，特に癌が表面にほとんど露出していない場合，通常の内視鏡検査やEUSでは間葉系腫瘍との鑑別が困難で，生検でも癌と診断できない場合がある．今回，SMT様食道癌とSMTの鑑別において，EUSで1/9層が連続して視認できるかに注目して検討した．間葉系腫瘍のうち，平滑筋腫3例では1/9層が全例で明瞭に描出された．GCT3例では1/9層は描出されていたが，一部で菲薄化していた．SMT様食道癌11例では1/9層が全例で断裂，菲薄化していた．食道SMT様病変のEUSで1/9層に着目することで，質的診断につながる可能性があると考えられた．

　Mesenchymal tumors, primarily leiomyoma and granular cell tumor of the esophagus, show submucosal tumor（SMT）-like morphology, whereas esophageal cancer also shows SMT-like morphology. When the SMT-like esophageal cancer is not exposed on the surface, it is difficult to diagnose cancer by usual endoscopic examination or EUS, as well as biopsy. It is necessary to distinguish between SMT and SMT-like esophageal cancer using EUS. Our study focused on whether the first layer of the lesion can be recognized consecutively to distinguish SMT from SMT-like esophageal cancer.

　Out of the mesenchymal tumors, 1/9 layer was clearly recognized in all cases in 3 cases of leiomyoma. In 3 GCT cases, 1/9 layer was recognized, but it was partially thinned. SMT-like esophageal cancer 11 cases, 1/9 layer was torn and thinned in all cases. It is considered that there is a possibility of leading to qualitative diagnosis distinguishing SMT-like tumor and SMT in focusing on 1/9 layer by EUS.