Poor concordance between sequential transbronchial lung cryobiopsy and surgical lung biopsy in the diagnosis of diffuse interstitial lung diseases

Rationale: The diagnostic concordance between transbronchial lung cryobiopsy (TBLC)—versus surgical lung biopsy (SLB) as the current gold standard—in interstitial lung disease (ILD) cases requiring histology remains controversial. Objectives: To assess diagnostic concordance between TBLC and SLB sequentially performed in the same patients, the diagnostic yield of both techniques, and subsequent changes in multidisciplinary assessment (MDA) decisions. Methods: A two-center prospective study included patients with ILD with a nondefinite usual interstitial pneumonia pattern (on high-resolution computed tomography scan) confirmed at a first MDA. Patients underwent TBLC immediately followed by video-assisted thoracoscopy for SLB at the same anatomical locations. After open reading of both sample types by local pathologists and final diagnosis at a second MDA (MDA2), anonymized TBLC and SLB slides were blindly assessed by an external expert pathologist (T.V.C.). Kappa-concordance coefficients and percentage agreement were computed for: TBLC versus SLB, MDA2 versus TBLC, MDA2 versus SLB, and blinded pathology versus routine pathology. Measurements and Main Results: Twenty-one patients were included. The median TBLC biopsy size (longest axis) was 7 mm (interquartile range, 5–8 mm). SLB biopsy sizes averaged 46.1 6 13.8 mm. Concordance coefficients and percentage agreement were: TBLC versus SLB: k = 0.22 (95% confidence interval [CI], 0.01–0.44), percentage agreement = 38% (95% CI, 18–62%); MDA2 versus TBLC: k = 0.31 (95% CI, 0.06–0.56), percentage agreement = 48% (95% CI, 26–70)%; MDA2 versus SLB: k = 0.51 (95% CI, 0.27–0.75), percentage agreement = 62% (95% CI, 38–82%); two pneumothoraces (9.5%) were recorded during TBLC. TBLC would have led to a different treatment if SLB was not performed in 11 of 21 (52%) of cases. Conclusions: Pathological results from TBLC and SLB were poorly concordant in the assessment of ILD. SLBs were more frequently concordant with the final diagnosis retained at MDA.