serrated adenoma由来の癌の組織学的特徴と細胞分化について

Colorectal Adenocarcinoma of Common Cell Lineage to Serrated Adenoma: A Special Reference to Its Histologic Features and Cell Differentiation

要旨　鋸歯状腺腫（serrated adenoma；SA）または過形成性（化生性）ポリープ（hyperplastic or metaplastic polyp；H/MP）と同じ細胞系列上にあると考えられた癌（SA・H/MP由来の癌）の病理組織学的特徴と細胞分化を解析した．症例は70歳，女性．切除された右側結腸に6個の癌を認めたが，SAとH/MPも多発したことに加え癌の3病変にSAあるいはH/MP成分を伴うことからそれらはSA・H/MP由来であることが示唆された．更にこれらの癌は，①癌腺管のSA類似の鋸歯状構造，②特徴的なレース状の構造，③著明な浸潤性発育と先進部での脱分化，④免疫組織化学的にpS2およびhuman gastric mucinの発現，という共通する組織像と免疫組織化学的特徴を有し，それらの所見がSA・H/MP由来の癌の抽出に有用であると考えられた．

　The histological features and cell differentiation of carcinomas of the same cell lineage as hyperplastic (metaplastic) polyp (H/MP) or serrated adenoma (SA) were examined. A seventy-year-old woman had a right hemicolectomy. Six carcinomas were recognized in the resected colon. These carcinomas were considered to be of the same cell lineage as the SA and H/MP because of occurrence of multiple SAs and H/MPs as well as the co-existence of SA and H/MP areas in the carcinomas. These carcinomas had common histological and immunohistochemical features as follows, 1) a serrated structure resembling SA, 2) a lace-like structure, 3) infiltrative growth among the muscularis propria with dedifferentiation at the invasive front, 4) immunohistochemical expression of pS2 and human gastric mucin. These findings are useful for detecting carcinomas of the same cell lineage as the SA and H/MP.