—大腸上皮性ポリープの鑑別診断—非腫瘍性ポリープ—病理診断の立場から

Pathological Differential Diagnosis of Colorectal Epithelial Non-neoplastic Polyps

要旨●大腸の上皮性非腫瘍性ポリープの概要と鑑別疾患について記述した．本稿ではPeutz-Jeghersポリープ，若年性ポリープ，粘膜脱症候群（隆起型），colonic muco-submucosal elongated polyp，inflammatory myoglandular polyp，炎症性ポリープ，憩室内翻，虫垂内翻について取り扱った．大腸上皮性非腫瘍性ポリープは，原因が多彩で比較的まれなものも多く，内視鏡的には腫瘍性ポリープとの鑑別が問題となる病変も多い．病変の成り立ちから，病理組織学的には粘膜筋板の走行異常や炎症の多寡の所見によりおおよその鑑別が可能となる．大腸上皮性非腫瘍性ポリープの基本的な肉眼所見や病理組織学的所見を理解することにより，大腸ポリープ全体の内視鏡診断，病理診断に生かすことができる．

　This study aimed to describe the macroscopic and microscopic appearance and differential diagnosis of epithelial non-neoplastic polyps of the large intestine. We herein discussed Peutz−Jeghers polyp, juvenile polyp, mucosal prolapse syndrome（protruded type）, colonic muco-submucosal elongated polyp, inflammatory myoglandular polyp, inflammatory polyp, inverted diverticulum, and inverted appendix. Colorectal epithelial non-neoplastic polyps may be formed due to various reasons, many of which are relatively rare. Furthermore, certain lesions are endoscopically difficult to distinguish from neoplastic polyps. Histologic rough differential diagnosis can be made on the basis of the structure of the lesion, abnormalities in the running of the muscularis mucosa, and the presence or absence of inflammation. Understanding the basic macroscopic and histological findings of colorectal epithelial non-neoplastic polyps can be helpful in the endoscopic and pathological diagnosis of colorectal polyps as a whole.