Ⅱa＋Ⅱc型早期胃癌を疑わしめた異型上皮病変の1例

A Case of Atypical Epithelium of the Stomach Simulating Type Ⅱa+Ⅱc Early Gastric Cancer

　最近の胃X線・内視鏡検査の進歩は著しく，胃疾患の形態学的な診断能は飛躍的に向上した．その結果，最近では数多くの早期胃癌が発見されるようになった．ことに胃隆起性病変の質的診断は，比較的小さな1型ないしⅡa型早期胃癌の鑑別診断を除けば，比較的容易であると考えられている．

　今回，筆者らはⅡa＋Ⅱc型早期胃癌様の形態を呈した興味ある胃隆起性異型上皮病変を経験したので報告する．

　A protruding lesion of atypical epithelial nature resembling Ⅱa+Ⅱc type early gastric cancer was encountered in a 61-year-old man who had visited our out-patients' clinic with a complaint of full sensation in the abdomen. The lesion was located on the posterior wall of the pyloric antrum.

　X-ray and endoscopy of the stomach revealed a plateau-like protruding lesion with central shallow concavity localized on the posterior wall of the antrum. Not only because of its shape but also because of surface irregularity and its size (2.5×1.5cm), Ⅱa+Ⅱc type early cancer was most suspicious. On the other hand, its elevation was less rigid and fairly above the usual height of Ⅱa+Ⅱc, so that a benign epithelial growth could not be excluded as well. Gastric biopsy also proved negative for cancer. Only moderate atypia was recognized in the tissue taken from the central depression.

　Ninety nine cases of protruding epithelial lesions of the stomach experienced so far in our department have been classified according to their shapes on the basis of our criteria. Plateau-like elevations with central concavity were invariably malignant, their surface ranging from granular to nodular irregularity. In lesions with protrusions more than 1 cm in diameter, some advanced carcinomas were observed.

　Correlation of the present findings with those mentioned above has shown that in spite of our negative results for cancer they did not in the least furnish enough evidence to rule out malignancy.

　Histological study of the removed stomach revealed no demonstrable evidence of cancer in the elevated part. Only atypical epithelial nests belonging to Group Ⅲ were seen in the superficial layer of the mucosa.