Ex vivo confocal laser scanning microscopy – a potential tool for histological rapid on-site examination in Interventional Pulmonology

Confocal laser scanning microscopy (CLSM) offers real-time imaging of untreated human tissue with near-histological precision. Our aim is to assess the concordance between ex vivo on-site CLSM (VivaScope 2500M-VivaScope GmbH) pathological evaluation of biopsies obtained through interventional pulmonology procedures and the definitive histological report. Specifically, we examined the presence or absence of malignancy, histotype classification and suitability for molecular analysis using next-generation sequencing (NGS), as well as for Programmed Death Ligand 1 (PD-L1) analysis. In this retrospective analysis 34 lung lesions and 10 lymph node biopsies were included. Biopsy methods comprised 21 fine needle aspirations, 15 forceps biopsies, 6 cryobiopsies and 2 core-biopsies. The definitive histological diagnosis showed malignancy in 30 cases, benign findings in 5, while 9 samples were inconclusive. Diagnostic concordance was 97,7% (43 out of 44) since ex vivo CLSM missed one squamous carcinoma. Histotype discrepancies occurred in 2 cases. All 24 neoplastic samples suitable for NGS and PD-L1 analysis were identified by ex vivo CLSM. This study marks the inaugural use of VivaScope for Histological Rapid On-Site Evaluation (hROSE) in interventional pulmonology, demonstrating high agreement with definitive histological results and final suitability assessment for molecular testing. <fig><object-id>erj;64/suppl_68/PA2566/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig>