ﾌﾟﾛﾊﾞﾝﾄﾞの内視鏡所見から遺伝性びまん性胃癌が強く疑われた2つの独立した家族

Two independent families with strongly suspected hereditary diffuse gastric cancer based on the probands' endoscopic findings.

• Moriya Iwaizumi
• Hidetaka Yamada
• Misaki Fukue
• Yasuhiko Maruyama
• Ayano Sonoda
• Mitsushige Sugimoto
• Kenji Koda
• Ryoji Kushima
• Masato Maekawa
• Haruhiko Sugimura

抄録

遺伝性びまん性胃癌（HDGC）は，常染色体優性遺伝パターンを有する遺伝性胃癌症候群の中で最も有名な疾患であり，CDH1の病原性生殖細胞変異を同定することで診断が可能である．本研究では、HDGCが強く疑われる2つの独立した家族について報告する。更新されたInternational Gastric Cancer Linkage Consortium（IGCLC）のHDGCに関する臨床ガイドライン（2015年）では、スクリーニング／サーベイランス内視鏡検査の実施が明記されているが（Cambridge protocol）、今回報告された2家族で得られた内視鏡所見は、SRCCの存在を示す青白い部分を疑うべきであり、HDGCが疑われる症例では、正確な家族歴を得ることに加えて、生検を実施すべきであることを示唆している。

Hereditary diffuse gastric cancer (HDGC) is the most famous of hereditary gastric cancer syndromes with an autosomal dominant inheritance pattern, and its diagnosis can be made by identifying a pathogenic germline variant in CDH1. We report two independent families that were strongly suspected of having HDGC based on endoscopic findings (multiple tiny, pale areas) obtained in the probands; the probands were pathologically diagnosed as having signet ring cell carcinoma (SRCC) and were genetically confirmed to have a pathogenic CDH1 germline variant. Although the updated International Gastric Cancer Linkage Consortium (IGCLC)'s clinical guidelines for HDGC (2015) state that screening/surveillance endoscopy should be performed (Cambridge protocol), the endoscopic findings obtained in the two presently reported families suggest that pale areas should be suspected as indicating the presence of SRCCs, and biopsies should be performed in addition to obtaining a precise family history in cases suspected of having HDGC.