右側結腸における過形成性ポリープからみたSSA/Pとの関連性に関する検討

Analysis about the Association with Hyperplastic Polyp and SSA/P in the Right Side Colon

要旨　大腸の過形成性ポリープ（hyperplastic polyp ; HP）は元来，非腫瘍性ポリープとして取り扱われてきたが，近年，臨床病理学的，分子生物学的な多方面からの検討により，鋸歯状腺腫との関連が指摘されている．当センターにおいて，右側結腸に存在するHPで，拡大内視鏡観察後に内視鏡的切除を行った44病変をMVHP（microvesicular HP）群，GCHP（goblet-cell rich HP）群，MPHP（mucin-poor HP）群に亜分類し，その臨床病理学的，分子生物学的特徴について検討した．その結果，MVHP群の一部では存在部位やpit pattern，遺伝子背景においてSSA/P（sessile serrated adenoma）と相似性を示し，SSA/Pへ発育進展する可能性が示唆された．一方で矛盾点も存在し，また他のHPについてはまだまだ不明な点も多く，さらなる症例の蓄積とtranslational researchを通じた検討が望まれた．

　Originally HP（hyperplastic polyp）of large intestine was considered to be non-neoplastic polyp. But recently, association with HP and serrated adenoma is pointed out by clinic-pathology and molecular biology.

　We divided 44 HPs of right colon into three groups according to WHO classification to clarify their clinic-pathologic character, magnifying-endoscopic feature and genetic background.

　There were a lot of MVHP（microvesicular hyperplastic polyps）in appendix and ascending colon. In addition, magnifying-endoscopic feature of MVHP was type II-open or type II-long shaped pit pattern, and genetic mutation was BRAF.

　From a result of this study，it was shown that SSA/P and MVHP had similarity in location, pit pattern, and gene background.

　The possibility that MVHP grows in SSA/P was suggested. However, on the other hand, there are still many indistinct points about HP. It is desirable to continue a translational research in more large cases of HP in future.