悪性化した直腸深在性嚢胞性大腸炎の1例

Colitis Cystica Profunda with Malignant Change, Report of a Case

要旨　悪性化を示した深在性嚢胞性大腸炎症例を報告した．患者は36歳，男性で主訴は肛門からの腫瘤脱出．6年前に直腸ポリープの生検で粘膜層内の線維筋症から直腸粘膜脱の診断．4か月前から主訴があり当科を受診，直腸診で肛門から3cmの前壁に表面平滑弾性硬で，注腸造影でほぼ球形の，内視鏡では粘膜表面には異常のない，CTでは嚢腫状の腫瘤を認めた．1996年2月19日経肛門的腫瘤切除施行し，病理検査では粘膜上皮には異型性はなく線維筋症が認められ，粘膜下層内の嚢腫部分に高分化腺癌の所見が認められた．本例は直腸粘膜脱症候群が6年の経過で直腸深在性嚢胞性大腸炎の所見を呈しながら悪性化したまれな症例と思われ，非常に興味深い．

　A case of colitis cystica profunda suggesting malignant change is reported. Through histological examination six years previously, a 36-year-old male had been diagnosed as having the rectal lesion, mucosal prolapse syndrome with fibromuscular obliteration. He had prolapse of a tumor from the anus from four months previous to the most recent investigation. Rectal examination, barium enema, fiberscope and CT scan showed a cystic and elastic, hard tumor with smooth surface arising from the anterior wall of the lower rectum. He underwent transanal tumor excision on February 19th, 1996, and has survived well. Histology of the excised tumor revealed a non atypical epithelium, fibromuscular obliteration and submucosal cysts which show well-differentiated adenocarcinoma. This case is interesting because it suggests that mucosal prolapse syndrome can possibly undergo malignant change in the process of developing to colitis cystica profunda.