LAUSR

Recent years have seen a paradigm shift in the management of fibrosing interstitial lung diseases (FILD). It is now accepted that idiopathic pulmonary fibrosis (IPF) can be diagnosed by highresolution computed tomography (HRCT) when a typical pattern of usual interstitial pneumonia (UIP) is observed, and the clinical context is correct.1 In the absence of this pattern, as occurs in 50% of cases of IPF, surgical lung biopsy (SLB) is indicated.2 After IPF is diagnosed, drugs to delay disease progression (pirfenidone, nintedanib) can be given, contraindicated drugs can be avoided, patients can be included in clinical trials, and strategies for early inclusion in transplant programs can be implemented.3 Despite the importance of a specific histological diagnosis, the number of SBLs performed has steadily declined in recent years.4 Mortality associated with SBL is 1.7%, a rate that is far from imperceptible; morbidity is 30%, and includes pneumonia, persistent air leak, and respiratory failure. Morbidity and mortality increase significantly in older patients, and in individuals with functional respiratory decline and associated comorbidities.4 The introduction of lung cryobiopsy (LC), a semi-invasive endoscopic technique with significantly less morbidity and mortality than SBL and lower health costs, represents a great opportunity for increasing the number of cases of FILD with histological confirmation. Results obtained with LC are highly promising, as this technique offers the possibility of obtaining lung parenchyma specimens with a diagnostic yield of 70–85%.5 Indeed, some authors propose that SLB should only be considered in cases in which LC does not provide a specific diagnosis.6 However, before LC can be considered an alternative to SLB, prospective studies are needed to clarify a series of diagnostic and methodological issues. Diagnostic accuracy. The diagnostic accuracy of LC is unknown, and this information will be essential if we are to evaluate its real utility.7 This is of particular importance, since most published series include highly heterogeneous populations in which the diagnostic yield of LC may vary. Prospective studies must be performed in a single population of patients with suspected IPF to compare the results of LC with those of the gold standard SLB.7 Although some authors claim that this comparative study would be difficult to conduct for ethical reasons, it may be wrong to assume that LC offers