自然消褪した若年性ポリポーシスの1例

Juvenile Polyposis with Spontaneous Disappearance of Some of the Polyps, Report of a Case

要旨　患者は29歳の女性．約10年前より胃内の多数の隆起性病変を指摘されていたが，低蛋白血症が出現したため，1999年3月に当院に紹介された．消化管検査にて胃と大腸に多発性ポリープを認め，診断的内視鏡的粘膜切除術を行い若年性ポリポーシスと診断した．経過観察していたところ，8か月後に胃ポリープは著明に消褪し，同時に幽門輪上に基部を持つ0Ⅰ型早期胃癌の存在が明らかとなり，幽門側胃切除術を行った．これまで若年性ポリポーシスにおいて本例のように自然消褪した報告はない．

　A 29-year-old woman visited Shinshu University Hospital in March, 1999, complaining of general fatigue and body-weight loss. She had a 10-year history of unknown multiple gastric polyps. Laboratory studies showed a slight iron deficiency anemia and hypoproteinemia. Alpha-one-antitripsin clearance test showed that the hypoproteinemia in this case was due to protein losing gastroenteropathy. Barium meal examination and upper GI endoscopy revealed multiple gastric polyps, but gastric mucosa existing among the polyps was almost normal. Barium enema and colonoscopy showed some polyps. Diagnostic endoscopic mucosal resection was performed in the stomach and colon. Microscopic findings of the resected specimens revealed edematous change of mucosa and dilatation of capillaries on the surface of the polyps, but mucosa around the polyps was almost normal. These findings led to a diagnosis of gastrointestinal juvenile polyposis. After 8 months, multiple gastric polyps and some colonic polyps spontaneously improved, and anemia and hypoproteinemia lessened. However, a polypoid lesion prolapsing into the bulbus remained, and biopsy specimens obtained from it revealed poorly differentiated adenocarcinoma. Distal gastrectomy was performed in January, 2000. Pathological examination showed that papillary adenocarcinoma, and moderately and poorly differentiated adenocarcinoma were mixed in the lesion, but these carcinoma cells were limited to the mucosa.

　Gastrointestinal cancer is often complicated in patients with juvenile polyposis, but spontaneous im-provement of multiple polyps is rare. This case may be the first report of spontaneous improvement in juvenile polyposis.