Idiopathic pulmonary fibrosis (IPF) is the commonest idiopathic interstitial lung disease (ILD). The diagnosis is determined by a usual interstitial pneumonitis (UIP) pattern on high resolution computed tomography (HRCT). Current guidelines advocate lung biopsy in patients with diagnostic uncertainty though biopsy can afford significant morbidity and mortality. We aimed to evaluate our practice in diagnosing IPF in relation to these guidelines.

Methods We evaluated our experiences in a multidisciplinary team (MDT) setting in a UK tertiary referral centre of 104 patients referred with a presumed diagnosis of IPF between November 2012 and July 2014.

Results After MDT discussion, 48.5% patients had definite UIP and 51.4% had possible UIP or fibrotic non-specific interstitial pneumonitis (NSIP) based on ATS/ERS criteria. Of the fifty-three patients with possible UIP/NSIP, fifteen (28%) patients had a lung biopsy. Twelve out of fifteen patients had UIP on biopsy (80%). One patient died and one suffered with chronic pain post-biopsy (13%). In the remaining thirty-eight (72%) patients, biopsy was not possible due to comorbidities or patient choice.

Of the thirty-eight patients with radiological diagnosis of possible UIP/NSIP, thirteen (34%) patients were deemed to have a clinical diagnosis of probable IPF after MDT discussion based on disease progression and age. Two (5%) patients were subsequently diagnosed as having a connective tissue disease and twenty-three (60%) patients were clinically diagnosed as NSIP based on response to immunosuppression and stability of lung function.

Conclusions Surgical lung biopsy is considered the gold standard within the diagnostic work-up when there is diagnostic uncertainty. However in our clinical practice over two thirds of patients are not suitable for biopsy due to comorbidities and patient choice. Our clinical experience of a high yield of UIP after biopsy in patients with a radiological diagnosis of possible UIP/NSIP and concerns regarding morbidity and mortality has altered our practice. We increasingly utilise clinical data regarding progression and failed response to immunosuppressive therapies to aid in the MDT diagnosis of IPF when there is diagnostic uncertainty. In the subsequent year, 8.7% of patients underwent biopsy versus 14.6%, reflecting a change in practice.