直腸の隆起性過誤腫性病変の1例

Elevated Hamartomatous Lesion of the Rectum, Report of a Case

要旨　排便時の出血を主訴とする40歳の男性の直腸に内視鏡で表面結節状の隆起性病変が認められ切除手術を受けた．病変は肛門より7cmの部位から全周性に12×5cmの範囲にわたる暗赤色の隆起であり，病理組織学的に粘膜下組織は著明に肥厚を示し，同部には壁の肥厚を示す動静脈および腫大した神経叢と太い神経線維束，更に脂肪組織，膠原線維などの増生が認められ，また，粘膜も肥厚を示し，軽度のfibromusculosisの像がみられた．この病変はmucosal prolapse syndrome of rectumやangiodysplasiaなどの疾患とは種々の点で異なっている．筆者らは本症例の病変は本来同部に存在する諸組織の混在した増生であることから過誤腫性の変化とみなしelevated hamartomatous lesion of the rectumと表現したい．

　An elevated lesion with a nodular surface was found during endoscopic examination of the rectum in a 40 year-old man whose chief complaint was bleeding at the time of evacuation. Accordingly, rectal resection was performed. The lesion, a dark red protuberance measuring 12 cm in length and 5 cm in diameter, included microscopically a marked thickening of the submucosal layer.

　Also noted microscopically were arteries and veins with thickened wall in varying degrees and hyperplasia of nerve plexus as well as large bundle of nerve fibers. Fatty tissue and collagenous fibers were also hyperplastic, and the mucosal layer was thickened with mild fibromusculosis. This lesion differs from mucosal prolapse syndrome of the rectum or angiodysplasia of the colon in various respects. In view of the fact that the lesion in this case represents hyperplasia of various tissues normally present at the site, the authers consider it as a hamartomatous change, i.e., an elevated hamartomatous lesion of the rectum.