診断困難な炎症性腸疾患の特徴

Inflammatory Disorders of the Intestine that are Difficult to Diagnose

要旨●炎症性腸疾患の診断は診断者の力量に大きく依存するが，診断困難な原因が病変自体にあることも多い．診断困難な病変としては疾患概念が未確立の疾患，既知の疾患の初期病変や非典型病変，病原体の証明が困難な感染症，複数の疾患の合併病変，想起することが困難な希少疾患が挙げられる．また途中で当初の診断が変更されたものや，ある疾患の疑診にとどまっている場合も診断困難例に含まれる．診断困難例は経過観察で解決する場合もあるが，さまざまな診断困難例のパターンを認識し，病変の分布や形態から可能な限り既知の疾患に当てはめていくことが重要である．既知の疾患概念から外れるものは特徴的な病像を抽出し，新たな疾患として類型を構築する必要がある．

　The diagnoses of inflammatory disorders of the intestine majorly depends on the ability of diagnosticians. However, diagnostic failures may be attributed to the nature of the lesions. Cases that are difficult to differentiate include unestablished entities, early stage or atypical presentations of known disorders, infections for which pathogen detection is difficult, coexistence of disorders, and rare disorders that are difficult to conceive. Cases in which the diagnoses changes over time as well as when a certain disease is suspected but not confirmed are also considered to be difficult cases. Follow-up observation may lead to correct diagnosis；however, various patterns of diagnostic difficulty should be recognized. Based on the distribution and morphological features of lesions, such cases should be classified into known disorders as far as possible. However, if the lesion patterns are completely different from those of known categories, they should be categorized as new entities.