胃前庭部全周にverrucous gastritis様の肉眼形態を呈したⅡa集簇型粘膜内癌の1例

Early Gastric Cancer of IIa Aggregated Polypoid Type Spreading in the Entire Antrum, Report of a Case

要旨　76歳女性の胃前庭部全周にⅡa集簇型を呈した表層拡大隆起型粘膜内癌の1例について，胃X線像，内視鏡像，病理組織学的所見を報告した．大小不同の類円形結節状の粘膜隆起が，胃前庭部から胃角へかけて全周に密集し，その幽門側境界は比較的明瞭であったが，噴門側では隆起が次第に小さく低くなり正常粘膜へ移行し，境界は不明瞭であった．なお，隆起の表面は平滑でびらんや潰瘍はみられなかった．組織学的には胃粘膜の表層上皮，腺窩上皮を置換したかのように，主として胃小窩上皮型の腺癌細胞から成る胃型の高分化型乳頭状腺癌が存在し，その噴門側境界は肉眼的境界よりもやや広く（11.0×12.2cm）不明瞭であった．当施設での過去15年間の早期胃癌は587例で，Ⅱa集簇型は5例，本例のような広範なⅡa集簇型早期胃癌は1例で，その頻度は早期胃癌症例の中の0.2％であった．

　We report here a case of early gastric cancer of IIa aggregated polypoid type limited in the mucosa of the entire antrum.

　The patient was a 76-year-old woman who presented with weight loss. X-ray examination revealed numerous nodular mucosal elevations involving the entire antrum (Figs. 1-3). Endoscopic study also showed the comparable lesions (Figs. 5 and 6). Examination of the biopsy specimen obtained from these lesions showed well differentiated papillotubular adenocarcinoma.

　Total gastrectomy with extended lymph node dissection (R₂) was performed on September 16, 1982. Resected specimen contained round and nodular mucosal elevations of different sizes aggregated in a circle from the antrum to gastric angle (Figs. 7 and 8).

　Histological study of the resected specimen revealed well differentiated papillotubular adenocarcinoma which mainly consisted of villotubular proliferation of foveolar epithelial type adenocarcinomatous cells (1y (－), v (－), INFα) (Figs. 9-11). No metastasis was found in the dissected lymph nodes.

　Postoperative course was uneventful with no evidence of recurrence.

　Of 587 patients with early gastric cancer experienced in the past 15 years at our hospital, 65 had type IIa including 5 with IIa aggregated polypoid type. However, IIa aggregated polypoid type with extensive spread was found only in this case with the frequency being 0.2％ of all the early gastric cancer cases at our hospital.