Ⅱa集簇型を呈した未分化型胃m癌の1例

Ⅱa-aggregated Polypoid Type of Poorly Differentiated Adenocarcinoma in the Gastric Mucosa, Report of a Case

要旨　患者は70歳女性．当院ドックで胃X線検査の異常を指摘され当院入院となる．胃X線，内視鏡検査で，幽門部前壁にⅡa集簇型を呈する病変を認めた．術前の生検では，粘膜表層部は腺窩上皮型の異型上皮に極めて類似した異型腺管で覆われ，粘膜深層部に印環細胞癌を認め，腺窩上皮（胃）型の異型上皮に印環細胞癌を併存したものと診断，手術を行った．術後の病理組織学的検索で，幽門部前壁の病変は，80×65mm大の1つの領域内に大小の結節状の隆起の多発集簇があり，Ⅱa集簇型胃癌と診断されたが，隆起部粘膜は，表層部で極めて分化した腺窩上皮型の分化型腺癌があり，中層から深層部にかけてその腺管構造が乱れ印環細胞癌に連続的に移行する像を認め，この印環細胞癌の粘膜内増殖が著明であった．このような組織像を示すⅡa集簇型胃癌症例は極めてまれであり文献的考察を加えて報告する

　A 70-year-old woman was admitted to our hospital for further examination of an abnormality of the stomach detected by health check-up. The roentgenogram and endoscopy showed Ⅱa-aggregated polypoid lesion in the anterior wall of the antrum.

　The preoperative biopsy showed foveolar-like atypical epithelium in the superficial layer of the mucosa and signet-ring cell carcinoma in the deeper layer. Based on these preoperative pathological diagnoses, gastrectomy was performed.

　Histological examination of the resected stomach showed nodules of various sizes aggregated in an area, 85×65 mm, of the anterior wall of the antrum. These lesions turned out to be Ⅱa-aggregated type early gastric carcinoma. Elevated portions consisted of two components: well differentiated adenocarcinoma resembling to foveolar epithelium in the surface layer, and signet-ring cell carcinoma and poorly differentiated adenocarcinoma in the middle and deep layer. The transition of these two components occurred gradually and continuously.