de novo CDH1遺伝子欠損印環細胞癌の1例

A Case of de novo CDH1 Gene Deletion Gastric Signet Ring Cell Carcinoma

要旨●患者は20歳代，女性．心窩部痛精査の上部消化管内視鏡検査（EGD）で胃体下部〜前庭部に多発する平坦な褪色調領域を認め，生検結果はいずれも印環細胞癌であった．背景胃粘膜はH. pylori（Helicobacter pylori）未感染であり，明らかな家族歴は有しないが遺伝性びまん性胃癌の孤発例が疑われ，腹腔鏡下胃全摘術を施行した．術後病理結果では計22か所の粘膜内にとどまる印環細胞癌を認めた．遺伝学的検査でCDH1遺伝子欠損を認め，de novo CDH1遺伝子欠損印環細胞癌と確定診断した．de novo CDH1遺伝子欠損印環細胞癌の報告例は非常にまれだが，H. pylori未感染胃癌の増加に伴い今後注意すべき疾患と考えられる．

　The case is a 20s female with epigastric pain. Upper gastrointestinal endoscopy revealed multiple flat discolored areas from the lower body to the antrum of the stomach. Biopsy results revealed signet ring cell carcinoma in all specimens. The background gastric mucosa was uninfected with Helicobacter pylori（H. pylori）. Despite of no obvious family history, a sporadic case of hereditary diffuse gastric cancer was suspected, and laparoscopic total gastrectomy was performed. Postoperative pathology results showed signet ring cell carcinoma confined to the mucosa at 22 sites. Genetic testing revealed CDH1 gene deletion, and ultimately the case was diagnosed as de novo CDH1 gene deletion signet ring cell carcinoma. Although this type of carcinoma is extremely rare, but with the increase in stomachs uninfected with H. pylori, it is considered a condition that requires attention in the future.