胃底腺分化を伴う胃上皮性腫瘍の病理組織学的分類と鑑別診断

Histopathological Classification and Differential Diagnosis of Gastric Epithelial Tumors with Fundic Gland Differentiation

要旨●近年，胃底腺型腺癌のみならず胃底腺型腺癌成分を伴うが腺窩上皮への分化も伴う胃底腺粘膜型腺癌もみられるようになり，それ以外でも胃底腺への分化を伴うさまざまな腫瘍が発見されるようになった．それらの代表的病変として胃底腺型胃癌（胃底腺型腺癌，胃底腺粘膜型腺癌）と胃型腺腫の病理組織学的特徴について解説し，臨床的取り扱い方針および今後の課題について考察した．さらに，これらと鑑別が必要な腫瘍および腫瘍様病変（神経内分泌腫瘍，胃底腺ポリープおよびPPI関連ポリープとその腫瘍化病変，ラズベリー様腺窩上皮型腫瘍，自己免疫性胃炎の萎縮粘膜，再生性変化を示す胃底腺粘膜）の病理組織学的特徴について解説した．

　Gastric adenocarcinomas of the fundic gland（GA-FG）and fundic gland mucosa（GA-FGM）types, as well as various other tumors exhibiting fundic gland differentiation have all recently been discovered. This paper examines the histopathological characteristics of GA-FG, GA-FGM, and gastric-type adenomas as representative lesions, while also discussing their clinical management and future issues. Furthermore, this study explains the histopathological characteristics of tumors and tumor-like lesions that must be differentiated from GA-FG, GA-FGM, and gastric-type adenoma, such as neuroendocrine tumors, fundic gland polyps, and proton pump inhibitor-associated polyps and their neoplastic lesions, raspberry-like crypt epithelial tumors, atrophic mucosa of autoimmune gastritis, and fundic gland mucosa showing regenerative changes.