The role of transbronchial biopsy in the diagnosis of diffuse parenchymal lung diseases: Con

The role of transbronchial biopsy in the diagnosis of diffuse parenchymal lung diseases: Con O papel da biopsia transbrônquica no diagnóstico das doenc ¸as difusas do parênquima pulmonar: Contra In order to engage in a focused pro/con debate, it is useful to summarize key points of agreement, before reviewing areas that remain contentious.It would be folly to deny that in certain scenarios in diffuse parenchymal lung disease (DPLD), the transbronchial biopsy (TBLB) has an invaluable diagnostic role.In DPLD, histological support for a specific diagnosis can be obtained using TBLB in 29---79% of cases. 1 This wide range reflects the multiplicity of factors influencing the yield of the procedure, including the distribution of the lesion (focal or diffuse), status of the immune system of the patient, small size of the obtained samples, confounding due to crush artifacts and failure to penetrate beyond the peribronchial sheath.2,3 Despite these limitations, we can all agree, based on diagnostic yields of 65---90% in selected conditions, 1 that TBLB is an appropriate first biopsy procedure in many patients in whom bronchocentric DPLDs are suspected, especially sarcoidosis and lympangitis carcinomatosis.In other disorders, TBLB appearances are not diagnostically definitive in isolation but allow the formulation of a confident diagnosis when integrated with clinical data (including bronchoalveolar lavage) and radiologic findings: this applies especially to cryptogenic organizing pneumonia 4 and, less often, to hypersensitivity pneumonitis.However, when it comes to the diagnosis of individual idiopathic interstitial pneumonias (IIPs), a very different consensus emerges.In the recently published guidelines for the diagnosis of idiopathic pulmonary fibrosis (IPF) 5 it was unanimously concluded that TBLB should not be used to provide histologic support for a diagnosis of IPF.We explore the rationale behind this recommendation, which is diametrically opposed to the ''pro'' view in these paired editorials.The practical value of making a confident diagnosis is to provide accurate information on the likely natural history and/or treated course of disease in an individual patient.Essentially, it can be argued that in DPLD, ''diagnosis is prognosis''.No diagnostic test has consistent value in suspected