未分化型小胃癌の臨床診断

Clinical Diagnosis of Undifferentiated-type Small Gastric Cancers

要旨　胃癌2,186例2,392病変を対象とし，未分化型癌の臨床病理学的特徴を明らかにし，未分化型小胃癌の臨床診断の実情を検討し以下のような結論を得た．①分化型癌と未分化型癌の比率は，全体では1.4：1であったが，隆起型を除くと1.1：1でほぼ同率となったが，1cm以下に限ると139病変：48病変（2.9：1）となり，未分化型癌の比率は激減した．②未分化型小胃癌は，体部大彎を中心とした粘膜ひだの著明な領域とそれに接する2cm以内の範囲に81％が，分化型小胃癌はそれより口側の領域に73％が存在した．③未分化型は，3mmまではほとんどが切除標本で肉眼での識別不能な病変（Ⅱb）であったが，5mmを超えると形態変化（陥凹周囲の隆起，粘膜集中像）が強くなり，臨床診断の容易な病変の頻度が増えた．

　We reviewed 2,392 lesions from 2,186 cases of gastric cancer, and discussed clinicopathological features of undifferentiated-type cancers.

　1) The ratio between differentiated-type and undifferentiated-type was 1.4: 1 in total, and was 1.1: 1 when elevated type were excepted. Limiting the lesions to small cancers less than 1 cm in diameter the ratio was 2.9: 1 (139 lesions: 48 lesions).

　2) Eighty one% of undifferentiated-type small gastric cancers were located within 2 cms of the area where mucosal fold is evident along the greater curvature of the body. On the other hand, 73% of differentiated-type cancers were located in the oral site of such areas.

　3) Undifferentiated-type cancers less than 3 mms in diameter were almost entirely Ⅱb lesions not detectable grossly. However, among those exceeding 5 mm in size, morphological changes (depression with surrounding elevation, fold convergence, etc.) became more apparent, and increased the number of cases which could be easily recognized.