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A4440 - Cryobiopsy Followed by Surgical Lung Biopsy or Autopsy: A Retrospective Case Series of Biopsy Concordance
Author Block: J. C. Hewlett, J. K. Pannu, J. A. Kropski, O. B. Rickman, F. Maldonado, R. J. Lentz; Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University Medical Center, Nashville, TN, United States.
Rationale: Transbronchial cryobiopsy (TBC) is an increasingly utilized technique to obtain biopsy samples via bronchoscopy for the assessment of diffuse parenchymal lung disease (DPLD). However, the data on diagnostic yield overall remain sparse, and there has been no direct comparison of cryobiopsy versus surgical lung biopsy (SLB) in individual patients. Evaluation of patients who undergo cryobiopsy and have subsequent pathologic samples obtained via SLB, lung transplant, or autopsy could provide valuable insight into the real value of cryobiopsy in the diagnosis of DPLD.
Methods: We identified patients who underwent TBC for indeterminate DPLD and subsequently underwent SLB, lung transplant, or autopsy at Vanderbilt University Medical Center. Variables examined included pre-biopsy diagnoses, radiographic features, pathological findings, post-biopsy consensus clinical diagnoses for both the cryobiopsy and subsequent pathological sample, date range between pathologic samples, and cryobiopsy procedural details.
Results: Among the 211 subjects who have undergone cryobiopsy at our institution, 9 total subjects had subsequent lung pathology obtained. Two patients underwent autopsy, one of which had concordant pathology for usual interstitial pneumonia (UIP) on cryobiopsy and autopsy. The other patient had no evidence of disease on cryobiopsy; autopsy after precipitous clinical decline revealed acute neutrophilic capillaritis. One patient underwent lung transplantation with explant and TBC pathology concordant for UIP. Six patients underwent SLB subsequent to TBC (2.8% of TBC cases), all of which were referred for diagnostic uncertainty following TBC. The median time between TBC and SLB was 46 days (range 3 - 475 days). Cryobiopsy in two cases revealed nonspecific small airway-centric inflammation, with concordant nondiagnostic pathological findings on SLB. In a third case, cryobiopsy revealed necrotic malignant cells; SLB established the diagnosis of pulmonary T-cell lymphoma. Sampling error was evident in 2 TBC cases. In one, a single cryobiopsy specimen was obtained due to procedural complication with diagnosis of UIP/IPF on SLB; in the second, cryobiopsy obtained normal parenchyma while SLB demonstrated organizing pneumonia. In the final case, TBC showed peribronchiolar metaplasia and adjacent active/organizing fibrosis without temporal heterogeneity or fibroblastic foci, with subsequent SLB showing spatial and temporal heterogeneity and multiple subpleural fibroblastic foci diagnostic of UIP.
Conclusions: Transbronchial cryobiopsy remains a useful tool for the assessment of diffuse parenchymal lung disease. In indeterminate cases, surgical lung biopsy appears to add value in a limited number of cases in our small series. Further confirmation is needed and a multicenter study is ongoing.