直腸肛門部病変の検査法と鑑別診断―内視鏡診断

Endoscopic Findings of the Anorectal Area

要旨　直腸肛門部は極めて狭い範囲でありながら，排便機能を有するなどの解剖学的特異性に加え，重層扁平上皮や円柱上皮など多彩な組織像を有することから多様な疾患の発生の場となる．内視鏡観察においては，このような特性を理解し見逃しのない検査を行う．さらに直腸肛門部にみられる炎症性疾患や腫瘍性疾患の診断は，この領域に特異的にみられる疾患も念頭に置き，病変の形態や局在性，および介在正常粘膜の性状を通常内視鏡観察にてとらえ，これに拡大内視鏡所見や超音波内視鏡所見を組み合わせて診断を行っていく．

　Even though the anorectal area is very small, because of its anatomical specificity, such as its defecatory function, and containing a variety of histological structures, including stratified squamous epithelium and columnar epithelium, it is the site of origin of various diseases. Understanding these characteristics, we perform tests during endoscopic examinations so as not to overlook them. Moreover, diagnosis of the inflammatory diseases and neoplastic diseases that are seen in the anorectal area requires that the diseases specifically seen in this region also be kept in mind. In addition, we identify the morphology of the lesions and properties of both the local and intervening normal mucosa by ordinary endoscopic examinations, and then make the diagnosis by considering the magnifying endoscopy findings or ultrasound endoscopy findings together with them.