腺腫の癌化と考えられたⅠ型早期胃癌の1例

Type I Early Gastric Carcinoma Developing from a Lesion Followed Up As Adenoma, Report of a Case

要旨　患者は71歳，男性．当院において1978年5月（61歳時）から1983年11月までの5年間，胃体下部大彎の小隆起性病変を，腺腫として経過観察された．1983年時，内視鏡的切除が予定されたが，患者が未受診のまま5年間経過し，初回から10年経過した1988年4月再来院した．病変は形態学的に著明に変化，増大し，癌の診断で内視鏡的切除を試みたが完全切除しえず，開腹手術した．組織学的には粘膜固有層内にとどまるⅠ型早期癌であった．術後の再検討では，当初の内視鏡所見および生検組織像は腺腫と一致する所見であったが，3年後の1981年の時点では，生検組織像から癌が強く疑われた．臨床的には，極めてまれとされる腺腫の癌化と考えられたため，若干の文献的考察を加え報告した．

　A 71-year-old man who had been followed endoscopically because of gastric adenoma from 1978 to 1983 visited our hospital in 1988 after five-year interval. The lesion was detected in 1978 as a flat elevated and slightly dome-shaped lesion localized in the greater curvature of the lower body. It looked whitish in comparison with the surrounding mucosa and measured about 6-7 mm in diameter. The size slightly increased and histological examination of the biopsy specimens also showed gradually increasing atypia in the first five years (Figs. 1-3).

　In 1988, after five-year interval, the lesion now looked nodular polypoid and larger, 40×30×20 mm in size. The histological examination of the resected specimen showed well differentiated intramucosal adenocarcinoma (Figs. 4-7).

　Clinically, we speculate that the carcinoma was a resuit of malignant change of a gastric adenoma in the course of ten years.