胃と腸55巻13号

2020年12月発行

今月の主題 大腸鋸歯状病変の新展開

主題研究

TSAの亜型—Mucin rich TSA

著者： 村上敬¹ 八尾隆史² 廣本貴史¹ 赤澤陽一¹ 福嶋浩文¹ 齋藤剛² 澁谷智義¹ 坂本直人³ 永原章仁¹

所属機関： ¹順天堂大学消化器内科 ²順天堂大学人体病理病態学講座 ³さかもと内視鏡クリニック

ページ範囲：P.1615 - P.1620

文献概要

要旨●大腸TSAの亜型として，近年，粘液豊富な杯細胞を特徴とするMR-TSAが提唱された．MR-TSAは，好酸性の吸収上皮細胞と比較して杯細胞が全体の50%以上を占めるものと定義される．臨床病理学的には，MR-TSAは通常型TSA（C-TSA）同様に男性優位で，左側大腸に好発する．粘液形質ではC-TSAは大腸型を示す一方で，MR-TSAは高頻度に胃腸混合型を示す．β-catenin核内発現は一部で認められ，MLH1発現は保持されている．遺伝子変異解析では，MR-TSAは高頻度にBRAF変異を認め，逆にKRAS変異は少ない．これらの所見は，MR-TSAがBRAF変異陽性のmicrosatellite stableを示す大腸癌の前駆病変となる可能性を示唆している．

参考文献

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