3) hyperplastic polyp, serrated adenomaの拡大内視鏡観察

Magnifying Endoscopy of Hyperplastic Polyps and Serrated Adenoma

要旨　hyperplastic polyp（HYP）とserrated adenoma（SA），tubular adenomaは内視鏡治療の有無を判断する意味で鑑別診断が重要である．HYPの拡大観察は鶴田・工藤分類ではII型pit patternを呈しtubular adenomaとの鑑別は容易である．SAはHYP類似のserrated hyper（SH）と，絨毛状構造から成るserrated villous（SV）とに分けられpit patternはIIIH型pit，IVH型pitに分類される．両者とも腺管開口部に"鋸の歯"のようなギザギザを認めることが特徴である．

　Hyperplastic polyps of the colorectum are considered benign lesions. In Kudo's classification of pit patterns, it has been suggested that pit pattern of type II is characteristic of non-neoplastic lesions such as hyperplastic polyps. The differentiation between non-neoplastic lesions and neoplastic lesions is easy. Fujii et al. classified the pit patterns of serrated adenomas as follows ; 1) type IIIH (fern-like) pit pattern as a swollen type II-like pit pattern, 2) type IVH (pinecone-like) pit pattern as a pineal pit pattern containing a hyperplastic component. We considered that serrated adenomas should be treated as tubular adenomas.