内視鏡的に切除しえた小児手拳大のcolonic mucosubmucosal elongated polyp（CMSEP）の1例

Endoscopic Removal of Colonic Muco-submucosal Elongated Polyp in the Sigmoid Colon, Report of a Case

要旨　患者は44歳の男性．腹部症状はなかったが，検診で便潜血陽性を指摘され，1997年1月大腸内視鏡検査を受けた．その際，S状結腸に脳回様の軟らかい，手拳大のポリープを認め，入院となった．大腸X線検査では，長径7cm，最大幅5cmの亜有茎性の隆起として描出され，頭部には数条の皺を認めた．体位と空気量により，可動性と形態の柔軟な変化がみられた．特製のジャンボスネアを用いて，内視鏡的に切除した．組織学的には隆起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と，脂肪組織の増生を伴った，浮腫状の疎性結合織から成り，真武らの提唱するcolonic muco-submucosal elongated polyp（CMSEP）に一致するポリープと考えられた．

　A 44-year-old man was admitted to our hospital for the purpose of further examination of a positive fecal occult blood test. Double contrast radiograph showed a large semipedunculated polyp, measuring 7 cm in length and 5 cm in width, in the sigmoid colon. Endoscopic examinations showed the lesion to be a semipedunculated protrusion covered by mucosa of normal appearance with slight erythema. Cerebriform appearance was observed at the head of the polyp. The large polyp was resected by endoscopic polypectomy using a large-sized snare, measuring 5cm in diameter. Microscopically, the resected polyp was characterized by submucosal tissue covered by normal mucosa without any neoplastic, hamartomatous, or inflammatory change. The submucosal layer was mainly composed of edematous loose fibrous connective tissue with dilated blood vessels and lymphatics. Thus, the resected polyp was diagnosed as colonic muco-submucosal elongated polyp (CMSEP), which Matake et al have proposed.