The Usefulness of a Transbronchial Lung Cryobiopsy for Diffuse Bronchiolitis.

We herein report four cases of diffuse bronchiolitis proven by a transbronchial lung cryobiopsy (TBLC). Based on various aspects, including the pathological findings, we definitively diagnosed two patients with diffuse panbronchiolitis (DPB) and the other two with primary ciliary dyskinesia (PCD). One of the DPB patients had more severe peribronchiolar fibrosis than the other, and the disease course was refractory to macrolide therapy. One of the PCD patients was additionally diagnosed with combined constrictive bronchiolitis. This report highlights the importance of a TBLC in the differentiation of bronchiolitis, suggesting its utility for helping pulmonologists formulate a treatment strategy.