潰瘍性大腸炎関連腫瘍の内視鏡診断

Endoscopic Diagnosis of Ulcerative Colitis-Associated Neoplasia

要旨●潰瘍性大腸炎関連腫瘍（UCAN）は慢性炎症を背景に発生し，散発性腫瘍と比較して病変形態が多様で，平坦型や境界不明瞭な病変が少なくない．そのため，早期病変の拾い上げと正確な質的および範囲診断には，高画質白色光観察を基盤に，拡大観察を併用した色素および画像強調内視鏡観察を組み合わせた総合的評価が重要となる．一方で，背景粘膜の炎症・再生変化により内視鏡像の解釈が難しい場面もあるため，必要に応じて生検による病理組織学的評価を併用し，診断精度を高めることが求められる．国際的なサーベイランス戦略と本邦からの知見を踏まえ，内視鏡的拾い上げと質的診断の要点を整理の上で，実践的な診断を行うことが望まれる．

　Ulcerative colitis-associated neoplasia（UCAN）develops in the context of chronic inflammation ; furthermore, compared with sporadic tumors, it exhibits a diverse morphology, frequently with flat or poorly defined lesions. Therefore, a comprehensive evaluation is needed for early detection and accurate diagnosis, specifically by combining white light imaging with magnification and image-enhanced endoscopy. However, underlying mucosal inflammation and regenerative changes can complicate endoscopic image interpretation. Accordingly, histopathological evaluation via biopsy is required to improve diagnostic accuracy. To achieve this, international surveillance strategies and findings from Japan should be examined, and a clear understanding of the key principles for endoscopic detection and characterization of UCAN is essential.