Helicobacter pylori陰性の胃に発生した胃型の低異型度分化型癌

Low Grade Differentiated Cancer with Gastric Phenotype Arising in Helicobacter pylori-Negative Stomach, Report of a Case

要旨　H. pylori陰性胃癌は胃癌の中でもまれで，従来の報告では未分化の陥凹型が多い傾向にあるとされている．しかし近年，頻度は低いものの，萎縮のない胃底腺領域に発生する隆起型の胃型の腺腫や癌の報告が散見される．今回，胃底部に発生したH. pylori陰性の0-IIa型病変を報告した．本例は白色扁平隆起性病変で，胃型の粘液形質を示す低異型度分化型癌であった．萎縮のない胃粘膜に発生する隆起性病変の鑑別診断には，胃型の隆起性胃癌や胃型腺腫も念頭に置くべきと思われる．

　Helicobacter pylori-negative gastric cancers are rare, and in many cases, they are macroscopically depressed type tumors ; histologically they can be categorized as diffuse type. Elevated lesions, which express gastric phenotype, in the non-atrophic fundic gland area have also been reported. Here we report a case of type 0-IIa early Helicobacter pylori-negative gastric cancer in the stomach. Pathological diagnosis of the case was a low-grade gastric differentiated tumor with gastric phenotype expression. It is thought that gastric tumor or adenoma with gastric phenotype expression should be taken into consideration in the differential diagnosis of the elevated lesion in non-atrophic gastric mucosa.