組織像でわかる感染性腸炎

Histology of Infectious Enterocolitis

要旨　感染性腸炎の動向を知るために，下部消化管内視鏡生検材料を用いて，広義の炎症性（虚血性病変を含む）腸疾患の組織診断が得られた症例の解析を行った．さらに組織像でわかる代表的感染性腸疾患について解説した．組織像で確定診断が可能な疾患は，腸結核，非定型好酸菌症，Whipple病，腸管スピロヘータ症，梅毒，巨細胞性封入体症，カンジダ症，アスペルギルス症，ムコール症，放線菌症，アメーバ赤痢，ランブル鞭毛虫症，クリプトスポリジウム症，イソスポーラ症，アニサキス症，糞線虫症，日本住血吸虫症，ビルハルツ住血吸虫症などである．組織像から疑診可能な疾患は，腸チフス，腸管出血性大腸菌O157：H7大腸炎，Clostridium difficile腸炎，エルシニア腸炎などが挙げられる．起因病原体を証明できない多くの感染性腸疾患は，組織学的に非特異性炎症像を呈するため診断が困難となりやすい．正確な診断のためには組織所見に加えて，臨床情報を十分加味することが特に重要である．

　In cases histologically diagnosed as inflammatory bowel disease（IBD）（including lesions from ischemic colitis）, biopsy specimens obtained by colonoscopy were analyzed to investigate predisposition to infectious enterocolitis. Histological findings of common IBD are also discussed. A number of diseases can be diagnosed histologically, including intestinal tuberculosis, atypical Mycobacterial infection, Whipple's disease, intestinal spirochetosis, syphilis, cytomegalic inclusion disease, candidiasis, aspergillosis, mucormycosis, actinomycosis, amebic dysentery, giardia lamblia infection, cryptosporidiosis, isosporiasis, anisakiasis, strongyloidiasis, Schistosomiasis japonica, Schistosomiasis haematobia, etc. A number of diseases can be diagnosed histologically with high probability, including typhoid fever, enterohemorrhagic Escherichia coli O157 : H7 colitis,Clostridium difficile colitis, Yersinia enterocolitis, etc. Many types of infectious enterocolitis show histologically nonspecific inflammations, and it is difficult to identify the pathogen responsible and therefore difficult to diagnose. A combination of clinical information and histopathology results is essential to make a correct diagnosis.