過形成性ポリープから発生したと考えられる隆起型早期胃癌の1例

Early Gastric Cancer Derived from a Hyperplastic Polyp, Report of a Case

要旨　患者は54歳，男性．1978年に集団検診で胃のポリープ様病変を指摘され，内視鏡下生検で過形成性ポリープの診断を受けた．その後6年間，主に内視鏡で経過観察されていたが，1984年になってポリープの大きさ，表面の性状に著しい変化がみられ，生検で高分化型腺癌と診断されたため胃亜全摘術が行われた．肉眼的には大きさ3.3×2.2×1.0(高さ)cmの，中心に軽度陥凹を伴う隆起性病変であった．病理組織学的には大部分が高分化型管状腺癌で占められていたが，周辺に過形成性変化が残っており，臨床経過からも過形成性ポリープが癌化したものと考えられた．なお，深達度はsmであり，リンパ節転移もなく8年後の現在再発を認めない．

　A case of early gastric cancer, which is thought to arise from a hyperplastic polyp, is reported.

　A 54-year-old male was diagnosed with a hyperplastic polyp by medical check-up in 1978. The lesion was located in the antrum and was about 1 cm in size. Annual endoscopic examination for the subsequent six years had not revealed any changes in size and histological examinations of the lesion except for slight changes in the macroscopic shape. In 1984, the biopsy specimen of the lesion disclosed well differentiated adenocarcinoma, and partial gastrectomy was performed. Macroscopic findings of the specimen showed an elevated lesion, 3.3×2.2×1.0 cm in size, with a small depression in the center. Microscopically, Most of the lesion was occupied by carcinomatous component, but hyperplastic lesion remained peripherally. The depth of invasion was limited within the submucosal layer, and no lymph node metastasis was detected.