胃型分化型早期胃癌の画像診断―X線を中心に

Macroscopic Features of Differentiated-type Carcinoma with Gastric Phenotype in Early Gastric Cancer

要旨　最近，胃型粘液を有する分化型癌の存在が報告され，その癌については境界不明瞭な形態であることやリンパ節転移を来しやすいことなどが指摘されている．今回われわれは，分化型早期胃癌の中で胃型の粘液形質のみを発現した12症例13病変の画像所見を検討した．癌病変の占居部位はU領域6病変，M領域4病変，L領域3病変であり，胃上部に多かった．12症例中7症例は癌病変が多発していた．また，長径が5cm以上の広範な病変が5病変にみられた．画像所見としては陥凹主体のものが8病変，隆起主体のものが3病変，平坦な形態が主体のものが2病変であった．病変の境界は不明瞭なことが多かった．内視鏡所見では病変の表面に光沢が保たれていることが多く，病変の色調は正色調が多かった．X線所見では境界が不明瞭な病変が存在するため，胃小区のわずかな乱れやバリウム付着異常，病変の境界に生じる粗大な顆粒状影などを詳細に読影する必要があった．

　Differentiated-type Carcinomas with Gastric Phenotype of the Stomach (DCGP) have been reported to have different clinicopathological features from other phenotypes of gastric carcinomas. To clarify the macroscopic characteristics of DCGP, twelve cases (13 lesions) of differentiated-type early gastric carcinomas with gastric phenotype (HGM＋, CD10－, MUC2－) were studied. Ten of 13 lesions were located on the proximal two thirds of the stomach. Seven of 12 cases had multiple lesions of carcinoma and five lesions were spread widely in an area with a diameter over 5 cm. Macroscopically, 8 lesions were depressed types, 3 were protruded types and 2 were superficial types. Most of the lesions revealed gross appearance without change in color as compared with the adjacent non-cancerous areas. Since the lesions of DCGP had indistinct margins, it is necessary to notice any slight abnormality in the gastric area, abnormal Barium adhesion and granular mucosa in the margin of the lesions for accurate diagnosis.