SinoXivLuminal-Surface Claudin18.2 Expression Distinguishes Distal-Type Bronchiolar Adenoma from Mimicking Lesions: An Immunohistochemical Study
Abstract
Background Distal-type bronchiolar adenoma (BA) is a benign lung neoplasm characterized by a bilayered structure. However, atypical variants lacking continuous basal cell layers pose diagnostic challenges, particularly in distinguishing them from adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA), and invasive lung adenocarcinoma (ILA) with acinar and papillary growth patterns.Aim To investigate the immunohistochemical (IHC) expression of claudin18.2 in distal-type BA and assess its diagnostic utility in differentiating BA from histologic mimics.Methods Distal-type BA, atypical distal-type BA, AIS, MIA, and ILAs with acinar and papillary growth patterns were collected and subjected to IHC staining for claudin18.2.Results Claudin18.2 was expressed in all distal-type BAs (100%, n = 6), including 3 atypical variants, with characteristic weak-to-moderate luminal-surface positivity. In contrast, AIS and MIA cases showed lateral and basal membrane staining (100%, n = 6), whereas the ILA cases were negative (0%, n = 3).Conclusion Claudin18.2 may serve as a valuable IHC marker for diagnosing distal-type BAs and distinguishing atypical variants from their histologic mimics.
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Citation Information
@article{linxiangling2026,
title={Luminal-Surface Claudin18.2 Expression Distinguishes Distal-Type Bronchiolar Adenoma from Mimicking Lesions: An Immunohistochemical Study},
author={Lin Xiangling and Xie Chuyu and Zhang Tingzhen and Liao Dingzhun and Li Xiangyun and Qin Changfei},
journal={Research Square},
year={2026},
doi={https://doi.org/10.21203/rs.3.rs-9167542/v1}
}
