collagenous colitisの内視鏡所見と病理組織学的検討

Endoscopic Features and Histological Findings in Collagenous Colitis

要旨　CC（collagenous colitis）は内視鏡的特徴に乏しい原因不明の慢性下痢症と位置付けられていたが，近年，内視鏡診断・技術の進歩により，その微細な粘膜異常所見や特異な縦走潰瘍を呈することが知られ，またNSAIDsやPPIなどの薬剤との関係も報告されるようになった疾患である．その確定診断は病理診断によるCB（collagen band），単核球浸潤の証明に頼らざるを得ないのが現状であり，より効率のよい精度の高い生検診断を行う必要がある．本稿ではCC 15症例の内視鏡所見と病理組織学的所見を対比させ詳細に解析した．その結果，微細顆粒状粘膜では単球をはじめ各炎症細胞浸潤が有意に多く，かつ，CB陽性率が高く，CB形成との強い相関が証明された．このことよりCCが疑われる症例に対しては，微細顆粒状粘膜が好発する深部大腸の観察と生検が有用であると考えられた．

　Collagenous colitis is a bowel disease of unknown etiology reported by Lindström in 1976. It is a disease that generally presents with chronic diarrhea, but without endoscopic findings. Diagnosis is usually on the basis of histopathological evidence of collagen bands in the subepithelium of the colon.

　Recently, the colonoscopic endoscope has markedly improved the diagnosis of colonic inflammatory disease. Specific endoscopic features of collagenous colitis are coarse and nodular surface of the mucosa, red spots, aphthoid lesions, mucosal tears, crowded tortuous vascular pattern, and diffuse mucosal cloudiness. In this article, we analyzed the difference between endoscopic features and histological findings in the fifty-six slides results showed that from the mucosal biopsies in 15 collagenous colitis patients. In the results, significant correlations were present between inflammatory variably increased intraepithelial mononuclearcytes and the thickness of collagen bands in the coarse and nodular surface of the mucosa. In conclusion, if we suspect collagenous colitis, we should investigate the detailed endoscopical observation and the mucosal biopsies in the proximal colon where the coarse and nodular surface of the mucosa exists.