胃と腸43巻13号

2008年12月発行

今月の主題 大腸癌の発生・発育進展 主題

大腸鋸歯状病変における発育進展・癌化―臨床の立場から

著者： 樫田博史¹ 池原伸直¹ 工藤進英¹ 浜谷茂治²

所属機関： ¹昭和大学横浜市北部病院消化器センター ²昭和大学横浜市北部病院病理科

ページ範囲：P.1897 - P.1910

要旨　大腸鋸歯状病変をSA，THP，AHPの3群に分けて検討した．SA，THP は左側結腸に多いが，AHPは右側結腸に多かった．肉眼形態では，SA では隆起型が，THP，AHPでは平坦型が多かった．色調では，SAは発赤型が，THP，AHPは褪色・常色調が多かった．平均腫瘍径は，SA，AHPがTHPより有意に大きかった．拡大所見では松毬状や羊歯状を呈した病変の約90％がSA であり診断容易であるが，星芒状を呈した病変にはTHP以外にAHP，SAも少なからず含まれ診断困難であった．SAにはTHP由来とそうでないものがあると考えられた．鋸歯状病変の担癌例を13例経験した．5mm以上のSAのうち6.3％，5mm 以上のAHP中7.4％であったが，同時期の早期大腸癌 991 病変中1.1％，0.2％を占めるにすぎなかった．担癌 AHP 病変には SA 部分を認めず，SAを介した癌化とは別の pathway が存在するのではないかと思われた．鋸歯状病変の病理診断基準には大きな混乱が存在する．概念の整理・統一と，症例の集積が必要である．

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