過形成性胃ポリープの経過観察中に，その近傍に発生したと考えられた2個のポリープ癌

Malignant Transformation of Hyperplastic Gastric Polyp, Report of a Case

要旨　過形成性胃ポリープの癌化の可能性およびその病理組織学的判定基準，癌化率などについては現在なお問題がある．われわれは胃集検にて発見され初同精密検査で有茎性の過形成性胃ポリープと診断された病変が6年間，3回の経過観察後に著明に形態が変化し，切除標本では長い茎の上に1個の良性ポリープと2個のポリープ癌が独立して存在していた例を経験した．発生と発育を裏付ける明らかな資料はないが，臨床経過のうえではわれわれはこの2個の癌については初診時の良性の過形成陛ポリープの近傍に新たに発生した過形成性ポリープが癌化したものと考えた．この症例はポリープ癌の発生についての一資料となると思われる．

　It was observed that a case of a pedunculated hyperplastic gastric polyp, which was first detected by mass survey and consequently confirmed by the first close examination, underwent marked changes in its configuration during the three subsequent examinations over a period of six years. The resulting changes requested that a resection of stomach be performed, revealing that the case had developed the state of coexistence of a benign polyp and two lesions histologically diagnosed as a tubular adenocarcinoma, malignant change of hyperplastic gastric polyp.

　Analyses of clinical findings made us assume that the two polypoid carcinomas newly developed in the vicinity of the benign hyperplastic gastric polyp, which was detected during the first medical examination.

　The above case is considered to be of great interest when studying development of malignant change of benign polypoid lesion of the stomach.