腺領域からみた胃腺腫の診断

Clinicopathological Study of Gastric Adenoma in Relation to Two Diff erent Gastric Gland Areas

要旨　組織学的に胃腺腫と診断された78例83病巣を対象として，組織学的に腫瘍の周囲粘膜に胃底腺を認めるF型腺腫と胃底腺を認めないP型腺腫に分け，両者を臨床病理学的に比較検討した．F型が26.5％，P型が73.5％で圧倒的にP型が多かった．F型，P型の平均年齢はそれぞれ72.3歳，66.9歳でF型はP型より有意に高齢者に多かった．腺腫の肉眼型，大きさ，他部位胃癌合併率に関してはP型とF型で差を認めなかった．F型はC領域，M領域の大彎寄りに多く，P型はA領域とC領域，M領域の小彎寄りに多かった．F型，P型ともに周囲の粘膜固有腺の萎縮が高度で著明な腸上皮化生を伴った粘膜を背景として発生しており，すべて腸型腺腫であった．ただし，F型，P型とも約30％は一部に胃型形質を混じる不完全型腸型腺腫であった．周囲の腸上皮化生に関してF型は完全型が多いのに対してP型は不完全型が多い点，F型がP型に比して高異型度腺腫が多い点から，組織発生においてF型とP型で相違がある可能性が示唆された．

　Eighty-three lesions from 78 cases with gastric adenoma were classified into either F type adenoma, which occurred in the fundic gland mucosa, or P type adenoma, which occured in the pyloric gland mucosa. F type adenoma comprised 26.5% of the 83 adenomas, and P type adenoma comprised 73.5%. The average age of patients with F type adenoma was 72.3 years, while that of patients with P type adenoma was 66.9 years. As regards gross type, size and frequency of an association with gastric cancer in another site, no differences were obsersed between F type and P type adenoma. We assessed the site distribution of gastric adenoma according to CMA classification. The majority of F type adenoma occurred in the greater curvature of C area or M area, while the majority of P type adenoma occurred in A area or in the lesser curvature of C area or M area. The majority of both F type and P type adenoma arose in severely atrophic gastric mucosa with marked intestinal metaplasia. All of the 83 adenomas were of intestinal type but approximately 30% of them were incomplete intestinal type. F type adenoma had complete type of intestinal metaplasia surrounding it while P type adenoma more frequently had incomplete intestinal metaplasia. As regards grade of atypia of the adenoma, F type adenoma had severe atypia more frequently than P type adenoma.