発症初期から典型像形成に至る経過を観察しえたcap polyposisの1例

Cap Polyposis which Suggest Its Natural History, Report of a Case

要旨　患者は49歳，女性．下痢を主訴に受診した．大腸内視鏡で中部～上部直腸に広範な発赤とリンパ濾胞と考えられる白斑の多発を認めた．10か月後，再度下痢のため行った大腸内視鏡では，直腸に不整形の発赤がみられたが初回よりは範囲が縮小していた．20か月後に再び下痢増悪のため行った大腸内視鏡では，中部～上部直腸に背の低い隆起が多発し，表面に付着した粘液を除去すると発赤したびらん面が現れた．生検で確診がつかずEMRを行った結果，腺管の過形成と粘膜表層の肉芽組織がみられcap polyposisと診断した．本症の初期像から典型的病像が完成されるまで追跡された症例の報告はなく，貴重な症例と考えられたので報告した．

　A 49-year-old woman came to our hospital complaining of diarrhea. Colonoscopy revealed a wide reddish mucosa from the middle to the upper portion of the rectum, in which numerous white spots, probably corresponding to lymph follicles, were observed. Ten months later, she visited the hospital again because of worsening of her diarrhea. The second colonoscopy revealed irregularly-shaped reddish areas in the same region. Twenty months later, she visited our department again because of the same reason. The third colonoscopy showed multiple prominences covered with white mucus. A red erosion was disclosed by removing the mucus by water. As the histology of biopsy specimens was not sufficiently diagnostic, EMR was performed. Histological examination of the specimen showed elongated and dilated crypts and granulation tissue in the superficial portion of the mucosa, and the diagnosis of cap polyposis was confirmed. There are no reports describing the early phase of this disease. Our case was considered important in that the process of the formation of the typical polypoid prominences could be traced.