Role of Transbronchial Lung Cryobiopsies in Diffuse Parenchymal Lung Diseases: Interest of a Sequential Approach

Abstract

Background. Transbronchial lung cryobiopsies (TBLCs) are a promising diagnostic tool in the setting of diffuse parenchymal lung diseases (DPLDs). However, no comparison with surgical lung biopsy (SLB) in the same patient is available. Methods. The diagnostic yield and safety data of TBLCs, as well as the result of SLB performed after TBLCs, were analysed in a multicentric Belgian study. A SLB was performed after TBLCs in absence of a definite pathological diagnosis or if a NSIP pattern was observed without related condition identified following multidisciplinary discussion. Results. Between April 2015 and November 2016, 30 patients were included. Frequent complications included pneumothorax (20%) and bleeding (severe 7%, moderate 33%, and mild 53%). There was no mortality. The overall diagnostic yield was 80%. A SLB was performed in six patients (three without definite histological pattern and three with an NSIP). The surgical biopsy changed the pathological diagnosis into a UIP pattern in five patients and confirmed a NSIP pattern in one patient. Conclusion. TBLCs are useful in the diagnostic work-up of DPLDs avoiding a SLB in 80% of the patients. However, surgical biopsies, performed as a second step after TBLCs because of an indefinite diagnosis or a NSIP pattern, provide additional information supporting the interest of a sequential approach in these patients.

Figure 1

Algorithm summarizing the study protocol. DPLD: diffuse parenchymal lung disease; MDD: multidisciplinary discussion; SLB: surgical lung biopsy; NSIP: nonspecific interstitial pneumonia; TBLC: transbronchial lung cryobiopsy.

Figure 2

Detailed diagnoses obtained after TBLCs (and SLBs when applicable).

Figure 3

Illustration of the additional information obtained from surgical biopsy after cryobiopsies showing an NSIP pattern. A 75-year-old woman with idiopathic interstitial pneumonia had a chest CT scan showing an inconsistent UIP pattern (subpleural and basal reticular opacities, traction bronchiectasis, and ground glass opacities with an extent greater than reticular abnormalities without honeycombing) (a). TBLCs were performed in the left lower lobe and the pathological analysis identified an NSIP pattern (hematoxylin and eosin staining, magnification ×40) (b). The NSIP pattern was characterized by the presence of an interstitial septal thickening preserving the alveolar architecture, black arrow, with chronic inflammatory infiltrate, red arrow. Neither honeycombing nor fibroblastic foci were observed. A surgical lung biopsy was then performed in the same patient, in the same lobe (left lower lobe) showing a UIP pattern (hematoxylin and eosin staining, magnification ×40) (c). The photomicrography shows the presence of fibrotic changes with honeycombing (black arrow), heterogeneous architectural destructions and fibroblastic foci (enlargement and red arrow, magnification ×200). Those features were not observed on the cryobiopsy.