まれな大腸非腫瘍性疾患のX線・内視鏡診断

Radiographic and Endoscopic Diagnosis of Rare Non-tumorous Disorders of the Large Intestine

要旨●ある疾患が“まれ”である根拠を示すことは非常に困難である．その理由として，疾患がまれであるほど，データベースが確立されていないことが第一に挙げられる．次に，まれな疾患は特定の施設に集中しやすいという傾向がみられる．本稿ではまれな大腸良性疾患のうち，非腫瘍性の疾患を取り上げたが，炎症性と非炎症性に大別し，さらに病態別に分類を試みた．筆者がまれと考えた疾患のなかで，内視鏡を中心とした画像所見に特徴があるものを選んで解説したが，必ずしも疾患頻度を反映していない可能性があることを留意いただきたい．

　To present sufficient causes for the rarity of a certain disorder is a difficult task. The first reason for this is the lack of a database for these disorders. The second reason is that rare disorders have a tendency to concentrate to special facilities. This article deals with the rare, non-tumorous, benign disorders of the large intestine. The disorders were first divided into two categories：inflammatory and noninflammatory. Further classification was according to the pathophysiology. Among the disorders that the authors consider rare, those with characteristic findings in imaging were selected and explanations were added for the same. However, it should be understood that the list of rare disorders may not reflect the real incidences.