─特殊な組織型を呈する早期胃癌─Epstein-Barr virus関連胃癌・リンパ球浸潤癌

Epstein-Barr Virus-associated Gastric Carcinoma and Gastric Carcinoma with Lymphoid Stroma

要旨●胃のリンパ球浸潤癌は腫瘍組織内外にリンパ球浸潤が高度な組織型で，EBV（Epstein-Barr virus）感染が約8割に関連している．一方，EBV関連胃癌の約3割はリンパ球浸潤癌の組織像を呈する．EBV関連の早期胃癌の内視鏡所見では，粘膜下腫瘍要素を有する0-IIc型病変を示し，高度な発赤を伴う．リンパ球浸潤癌では軟らかい粘膜下腫瘍要素を有することが多い．近年ではEBV関連胃癌は分子生物学的観点からも胃癌の特徴的な一群であることが示され，治療につながる可能性が示唆されており，注目される組織型である．

　Gastric carcinoma with lymphoid stroma is a histologic subtype of gastric cancer with massive lymphocyte infiltration in and around the tumor tissues, relating to approximately 80% of EBV（Epstein-Barr virus）infections. On the contrary, approximately 30% of EBV-associated gastric carcinoma exhibits the histology of carcinoma with lymphoid stroma. The endoscopic findings of EBV-associated gastric carcinoma demonstrated 0-IIc lesions with a submucosal tumor element and strong reddening. Carcinoma with lymphoid stroma often encompasses elements of submucosal tumor. In recent years, the EBV-associated gastric carcinoma is shown to be a distinctive subtype of gastric cancer from a molecular biology perspective, suggesting the possibility of leading to more effective treatment. Therefore, gastric carcinoma with lymphoid stroma and EBV-associated gastric carcinoma notably are histologic subtypes of gastric cancer.