Bronchiolar adenoma/ciliated muconodular papillary tumor mixed with adenocarcinoma in situ in the same tumor
Suiha Uchiyama, Kenichi Mizutani, Eriko Suzuki, Naoko Yoshii, Takuya Watanabe, Hiroyuki Tsuchida, Shogo Yobita, Kensuke Iguchi, Minori Nakamura, Takumi Endo, Seishiro Takahashi, Hiroshi Ogawa, Masayuki Tanahashi
Abstract
Bronchiolar adenoma (BA)/ciliated muconodular papillary tumor (CMPT) is defined as a benign tumor composed of epithelial and basal cells. Recently, some cases with driver mutations or malignant transformation have been observed. Thus, whether BA/CMPT is benign or malignant remains controversial. We herein report an extremely rare case of a 68-year-old woman with a CMPT accompanied by adenocarcinoma in situ (AIS). BA/CMPT existed inside the AIS. The BA/CMPT component did not show any driver mutations; however, the AIS component had an EGFR driver mutation in exon 19. The accumulation of cases and further studies are needed to discuss the malignant potential of BA/CMPT.