Helicobacter pylori陰性の胃底腺領域に発生した0-I型早期胃癌の1例

Well-Differentiated Tubular Adenocarcinoma of the Stomach, Report of a Case

要旨　患者は60歳代，男性．2年前より他施設で胃ポリープを指摘されていたが，胃X線検診で異常を指摘され受診した．上部消化管内視鏡検査では，胃体上部前壁に発赤調で約10mm大の山田III型の隆起性病変を認めた．表面は，不均一な顆粒状～乳頭状構造を呈しており，背景粘膜は萎縮のない胃底腺領域で，H. pylori抗体は陰性であった．生検診断は胃型腺腫であったが，不整な表面構造から早期胃癌が疑われたため，内視鏡的粘膜切除術を行った．病理組織診断は，大小腺管状の異型度の低い胃型の高分化型管状腺癌であった．萎縮のない背景粘膜に発生したポリープの診断では，胃型の隆起型胃癌も念頭に置いて行う必要がある．

　A man in his 60s with gastric polyp found at another institution decided to come to our institution when abnormalities were found on gastric X-ray examination. Endoscopy of the upper gastrointestinal tract indicated an elevated lesion of Yamada III type polyp with mild redness on the anterior upper gastric wall. Its surface showed granular, mild papillary structures that were non-uniform in shape. The background mucosa was fundic gland region with no atrophy, and was negative for anti-Helicobacter pylori antibody. Based on biopsy, a diagnosis of gastric type adenoma was made. Based on the irregular surface structure, early gastric cancer was also suspected, and endoscopic excision was performed. On histopathological examination, large and small tubular gland-like, and gastric type, well-differentiated type tubular adenocarcinoma with low grade of atypism were observed on the outermost layer of the fundic gland mucosa.

　Gastric type gastric cancer should be considered in differential diagnosis of polyp-like lesions in background mucosa with no atrophy.