大腸炎の生検組織診断

Pathological diagnosis of coloproctitis in biopsy specimens

要旨

大腸炎を引き起こす代表疾患は炎症性腸疾患であるが，実際の診療では感染症や薬剤性といったさまざまな急性疾患を含む鑑別を行わなければならない。腫瘍性病変とは異なり，炎症性疾患では病変部から正確な組織生検が行われていても確定診断に至らないケースも決して少なくない。大腸炎の診断における誤診や未確診を防ぐためには，組織のみで確診の得られる疾患や，組織所見と内視鏡所見・臨床所見を併せて確診に至ることのできる疾患の確実な診断・除外が重要であり，また一般的に“非特異的な炎症像”を示すとされる疾患を非特異的ながらもある程度の分類を行うことが診断確定への鍵となる。本稿では病理報告書を読む際に内視鏡医が着目すべき組織所見について解説する。

　Inflammatory bowel disease is the most common cause of colitis, but in practice, it must be differentiated to include a variety of acute diseases, such as those that are infectious and drug-related. Unlike the diagnosis of neoplastic lesions, it is not uncommon for a definitive diagnosis of colitis to be missed even when an accurate tissue biopsy of the lesion is performed. To prevent misdiagnosis and missed diagnosis in cases of colitis, it is important to make a definitive diagnosis and exclude diseases that can be confirmed by tissue biopsy alone or by combining tissue findings with endoscopic and clinical findings to reach a definitive diagnosis. In addition, the key to confirming the diagnosis is to classify diseases that generally present as “nonspecific colitis” to some extent, even though they are not specific. In this article, we will discuss the histological findings that endoscopists should focus on when reading pathology reports.