Exclusion of other known causes of ILD such as certain drug toxicities, environmental exposures, and connective tissue diseases
Abnormal pulmonary function studies that include evidence of restriction (reduced VC, often with an increased FEV1/FVC ratio) and impaired gas exchange [increased P(A–a)O2, decreased PaO2 with rest or exercise or decreased DLCO]
Bibasilar reticular abnormalities with minimal ground glass opacities on HRCT scans
Transbronchial lung biopsy or BAL showing no features to support an alternative diagnosis
Patients with lesions on the chest radiograph should be discussed in a multidisciplinary meeting with a respiratory physician and radiologist at a minimum.
Percutaneous transthoracic lung biopsy (PTLB) should be considered in the following:
- New or enlarging solitary nodule or mass on the chest radiograph which is not amenable to diagnosis by bronchoscopy or CT shows it is unlikely to be accessible by bronchoscopy.
- Multiple nodules in a patient not known to have malignancy or who has had a prolonged remission or more than one primary malignancy.
- Persistent focal infiltrates, either single or multiple, for which no diagnosis has been made by sputum or blood culture, serology, or bronchoscopy.
- Hilar mass following negative bronchoscopy. Continue reading