十二指腸Peutz-Jeghers型ポリープの1例

Peutz-Jeghers-Type Polyp of The Duodenum, Report of a Case

要旨●患者は60歳代，男性．直腸癌の術後定期検査目的に行った造影CTで，十二指腸に腫瘤を指摘された．EGDで十二指腸下行部に基部を持つ20mm大の有茎性病変を認め，発赤調で分葉多結節状，表面には撒布性の白点を認めた．NBI併用拡大観察ではやや腫大した絨毛構造を認め，絨毛内のloop状の微小血管は口径不同，形状不均一などの異型に乏しく，また白色物質の局在が絨毛間質内に限局しており，リンパ流のうっ滞による所見と診断した．以上より，過誤腫性ポリープと診断し，内視鏡的ポリペクトミーを施行した．病理組織学的診断では上皮の過形成性変化と粘膜筋板由来の平滑筋の樹枝状増生を認めた．消化管ポリポーシスや皮膚所見，家族歴を認めないため，孤在性Peutz-Jeghers型ポリープと診断した．まれな十二指腸の孤在性Peutz-Jeghers型ポリープにおいて，NBI併用拡大観察が上皮性腫瘍との鑑別診断に有用であり，また病理組織学的所見との対比をし得た症例を報告する．

　A 60s male with a past history of rectal cancer surgery visited our outpatient department for a detailed examination. Contrast-enhanced computed tomography revealed a mass in the third portion of the duodenum. Esophagogastroduodenoscopy showed a pedicellate polyp（approximately 20mm）in the third portion of the duodenum. The polyp appeared leaf-like, was multi-tuberous, and had white spots. Magnifying endoscopy combined with narrow-band imaging disclosed a slightly swollen villous structure that exhibited a convoluted leaf pattern. The loop-formed microvessel in the villus lacked diameter inequality and shape heterogeneity. Biopsy findings only demonstrated a hyperplastic change in the villus epithelium. We suspected a hamartomatous polyp and removed it by endoscopic resection. Besides the histopathological finding of the hyperplastic change in the epithelium, there was tree-like arborization hyperplasia of the smooth muscle that was assumed to be of muscularis mucosae origin. The patient had no history of gastrointestinal polyposis, skin or mucous pigmentation, and familial diseases. We then made a diagnosis of a solitary Peutz-Jeghers-type polyp in the duodenum. These types of polyps are primarily detected in the large intestine, and a duodenal lesion is rare, which is reported here.