13年間の経過観察中に癌化を来した胃過形成性ポリープの1例

Gastric Hyperplastic Polyp with Focal Cancer: Malignant Transformation Was Recognized during the Course of 13 Years, Report of a Case

要旨　患者は64歳，女性．1976年に胃前庭部大彎に10mm大の有茎性で赤色調，表面平滑な過形成性ポリープを認めた．以後79，81，85年に内視鏡検査を施行し，いずれの時期も著変なく，生検はGroup Iで過形成性ポリープであった．ところが87年に隆起は増大し，このときの生検はGroup Iであったが，89年には隆起は更に増大し分葉傾向を示し，生検はGroup Vであった．内視鏡的ポリペクトミーを施行し，切除標本は大きさ25×17mm，病理組織学的には大部分は過形成で癌は表層の一部に認めるのみで，組織型tub₂，深達度m，v₀，ly₀であった．癌を一部に伴った胃過形成性ポリープの報告は散見されるが，癌化の過程を長期間にわたり内視鏡的に観察できた症例の報告は極めてまれであり，報告した．

　This paper is to demonstrate a case of hyperplastic polyp with focal cancer, in which malignant transformation was recognized during the course of 13 years.

　The patient was a 64-year-old female. A pedunculate reddish hyperplastic polyp, about 10 mm in size, was observed on the greater curvature of the pyloric antrum in 1976 (Fig. 1a, 4a). The patient underwent serial endoscopic examinations in 1979, 1981, 1985 (Fig. 1b～d), and each time histologic examination of biopsy specimen showed hyperplastic polyp (Fig. 4b). But the polyp increased in size in 1987 (Fig. 2a), and in addition to increase in size, an uneven lobulation was observed in 1989 (Fig. 2b), and this time, endoscopic biopsy specimen revealed cancer cells. Endoscopic polypectomy was performed in July 1989 (Fig. 3a, b). The size of the resected specimen was 25×17 mm and microscopic finding showed moderately differentiated adenocarcinoma on the surface of the hyperplastic polyp (Fig. 5a, b, Fig. 6). This case suggests that the increase in size and the appearance of lobulation may be the signs of malignant transformation of hyperplastic polyps, and these polyps should be resected by endoscopic polypectomy.