Clinicopathological and molecular features of bilayered and partial monolayered bronchiolar adenoma
MA Yixin
DONG Gongming
LI Xinyu
ZHANG Guanjuan
LI Luyao
Abstract：Objective To investigate the clinicopathological and molecular features of partial monolayered and bilayered bronchiolar adenoma(BA).Methods Surgical specimens of 5 partial monolayered cases and 5 bilayered cases were collected.The clinicopathological features were analyzed,and the expression of TTF1,CK5/6,p63,p40,CK7,and NapsinA were detected by immunohistochemistry.Gene mutations were tested by next generation sequencing(NGS).Results The bilayered cell structure and continuous basal cell layer were observed in bilayered cases.Partial monolayered BA showed partial basal cell loss and transition of bilayered structure and single-layered structure.The basal cells expressed CK5/6,p63,and p40,and TTF1 expressed in both basal cells and luminal cells.NGS showed one case of EGFR exon 19 deletion and one case of KRAS G13C mutation in 5 partial monolayered BAs.There was one case of KRAS G12C mutation and one case of BRAF V600E mutation in 5 bilayered BAs.All patients were followed up for 8 to 67 months,and no recurrence or metastasis occurred.Conclusion BA,especially partial monolayered BA,is a rare lung tumor that is easily confused with adenocarcinoma,and the comprehensive analysis of histomorphology and molecular genetics is crucial for distinguishing the nature of the lesion and avoiding misdiagnosis and missed diagnosis.
Keywords：Bronchiolar adenomaHistopathologyImmunophenotypeNext generation sequencingMutations
Publication Date：2025-07-28
Online Publishing Date：2025-08-27(First online date of this platform, not the publication date of the document)
Pages：7( 822-828 )