Usefulness of Surgical Lung Biopsies after Cryobiopsies when Pathological Results Are Inconclusive or show a Pattern Suggestive of a Nonspecific Interstitial Pneumonia

Abstract BACKGROUND The equivalence of transbronchial lung cryobiopsies (TBLCs) and surgical lung biopsy (SLB) in the diagnosis of diffuse parenchymal lung diseases (DPLDs) is still debated. The aim of this study was to evaluate the benefit of SLBs performed in selected patients after TBLCs.METHOD We conducted a multicentric Belgian prospective trial in which SLBs were performed after TBLCs when the pathological diagnosis was uncertain or if a nonspecific interstitial pneumonia (NSIP) pattern was observed hypothesizing that SLB could provide additional information and that a co-existent UIP pattern could be missed.RESULTS 81 patients with TBLCs performed for a DPLD were included in the study between April 2015 and December 2019. A specific histological diagnosis was obtained in 52 patients (64%) whereas no pathological diagnosis following TBLCs was obtained in 13 patients (16%) and a pattern suggestive of a NSIP observed in 16 patients (20%). 14 of these 29 patients had SLBs after TBLCs. SLBs showed a UIP pattern in 11 (79%), a pattern suggestive of a hypersensitivity pneumonitis in two and a NSIP pattern in one patient. Among the 16 patients with pathological NSIP following TBLCs, six benefited from SLBs showing a UIP in five and confirming a NSIP in only one patient. A retrospective pathological analysis of patients having both procedures showed lower diagnostic confidence and agreement among pathologists for TBLCs compared to SLBs. Major determinants underlying the added value of SLBs were, as expected, the bigger size and the subpleural localization of the biopsies.CONCLUSIONS TBLCs are useful in the setting of DPLDs with a good diagnostic yield. However, our study suggests that SLB provides critical additional information in case TBLCs are inconclusive or show a pattern suggestive of a NSIP, questioning the accuracy of TBLC to identify adequately this histological pattern.