緩徐に増大し診断に苦慮したbronchiolar adenoma/ciliated muconodular papillary tumor（BA/CMPT）の2例

Two cases of bronchiolar adenoma/ciliated muconodular papillary tumor（BA/CMPT）that grew slowly

Bronchiolar adenoma/ciliated muconodular papillary tumor（BA/CMPT）は2002年に石川らが初めて報告した疾患で，2021年改訂のWHO分類第5版で新たに記載されたまれな良性腫瘍である^1）。自覚症状はなく，検診などで偶発的に発見されることが多い^2）。今回我々は，緩徐に増大し診断に苦慮したBA/CMPTを2例経験したため，文献的考察を加えて報告する。

We herein report two cases of BA/CMPT that showed extremely slow growing and were difficult to be diagnosed preoperatively. BA/CMPT is a rare benign lung tumor that was firstly reported by Ishikawa et al in 2002 and included in the 5th edition of World Health Organization Classification published in 2021. BA/CMPT is commonly found in peripheral lung of middle-aged and elderly people and does not show any specific, image findings. It is difficult to differentiate it from lung cancer but extremely slow growing is a suggestive finding. This rare condition should be included in differential diagnosis for this kind of lung nodules.