粘膜と粘膜下層から成る長い有茎性ポリープの4例―colonic muco-submucosal elongated polyp（CMSEP）の提唱

Long Pedunculated Colonic Polyp Composed of Mucosa and Submucosa, Report of Four Cases: A Proposal of Colonic Muco-submucosal Elongated Polyp (CMSEP)

要旨　既存の分類に該当しない4例の大腸ポリープを経験した．いずれも2.5～16cmに至る細長い有茎性ポリープで，病理学的にもほぼ同一の組織像を示した．すなわち，ポリープの表面は正常粘膜に覆われ，粘膜下層は静脈とリンパ管の拡張を伴う浮腫状の疎性結合織から成り，正常の筋層は認めなかった．発生部位は全大腸にわたり，臨床的には49～79歳，女性3例と男性1例であった．このような組織像を示す，大きく長い茎を有したポリープの報告は現在までないが，1つのカテゴリーに入れて取り扱うほうが良いと考え，colonic muco-submucosal elongated polyp(CMSEP)と呼称することを提唱した．

　We report four cases with colonic polyps which cannot be classified by previously established criteria. All of these polyps have common macroscopic and microscopic characteristic features. First, they have an extremely long stalk, the length of which was 25 to 160 mm. Second, histological characteristics were edematous submucosa with dilated blood vessels and lymphangiectasia under the normal surface mucosa. This kind of polyp was differentiated clearly from the polyps with dysmature, neoplastic, hamartomatous, and inflammatory process. Our patients were aged from 49 to 79 years, and the average age was 62.3 years. Three of the four patients were female and one male. These polyps were located variously in the sigmoid, the descending, the transverse colon, and in the ascending colon. We named this polyp “colonic muco-sabmucosal elongated polyp (CMSEP)”, and would like to regard it not as an unclassified polyp but as a new entity.