胃型の高分化型早期胃癌の病理学的特徴

Well-differentiated Type Adenocarcinomas of Gastric Mucin Phenotype Transform into Intestinal Type Carcinomas

要旨　高分化型早期胃癌60例に対して，CD10，MUC2，MUC5AC，HGM，MUC6の粘液染色を行い，癌の粘液形質別頻度・粘液形質変化を検討した．陽性細胞数が5％未満を陰性とすると，胃型25％，胃腸型35％，小腸型40％であった．小腸型は，CD10陽性なら，同細胞の多寡に関係なく小腸型と定義したが，この中には胃型粘液を有するものが63％存在した．胃型形質癌の全例が5％未満のMUC2陽性細胞を有していた．胃型形質癌がMUC2陽性の腸型癌へ，さらにCD10陽性の小腸型癌へ進展する経路が推定された．

　We studied the frequency of well-differentiated type adenocarcinomas with gastric, gastrointestinal, and small-intestinal phenotypes in early gastric carcinomas as well as the change in mucin phenotype from one to another, using CD10, MUC2, MUC5AC, HGM, and MUC6 immunostains. 25％ of the cases we studied were of gastric type (with 5％ or more gastric type mucin), of 35％ gastrointestinal type (with 5％ or more MUC2 mucin), and of 40％ small-intestinal type (with CD10 positive cells, irrespective of their number) (Table 4). All of the gastric-type cancers had MUC2 positive cells of less than 5％, and 63％ of small-intestinal type-cancers had cells positive for gastric type mucin. It is suggested that gastric-type cancer may transform into gastrointestinal-type and then into small-intestinal-type one as seen in non-neoplastic mucosa.