側方表層進展を伴う胃腺腫（Ⅳ型）の1例

A Case of Benign Adenoma with Lateral Superficial Spreading

　われわれは胃ポリープを病理組織学的に分類しているが，なかでも腫瘍性ポリープ，とくにⅣ型ポリープの癌化の危険性が高いことを報告してきた．Ⅳ型ポリープはかなりの異型を示すので，病理組織学的に癌との鑑別が問題となることからも重要なポリープとして注目されている．

　最近われわれは組織学的にはどこにも癌と診断できる程の異型が認められないにもかかわらず，かなり広範囲の側方進展を示したⅣ型ポリープを経験したので，境界域病変として問題のある症例と考え報告する．

　Polypoid lesion was found radiologically and endoscopically in the posterior gastric wall adjacent to cardia in 79 aged female. From the biopsy specimen, a pathologist diagnosed this lesion as papillary adenocarcinoma. Proximal gastrectomy was performed.

　In the resected specimen 3×2 cm sized hemispherical polypoid lesion located in the posterior gastric wall, 2 cm distal from the esophagogastric junction.

　Flower bed like superficial lateral invasion was observed in 5×4 cm area surrounding the polypoid lesion.

　Histologically this polypoid lesion was diagnosed as papillary adenoma, and its histological appearance was much similar to the adenoma of the colon.

　Although definitely cancerous portion was recognized in no-where of this lesion, this adenoma showed lateral superficial spreading which was unusual in the benign lesion.