Thank you to Dr. Burnett who presented a complex pulmonary case in Intern Report today. The case allows for a refresher on idiopathic interstitial pneumonias and BAL results.
Idiopathic insterstitial pneumonias are a subset of diffuse instersitial lung disease with an inflammatory infiltrate in the interstitial compartment occasionally accompanied by fibrosis. Interstitial pneumonia can be idiopathic or associated with other conditions such as connective tissue disease, HIV, drugs or hypersensitivity. Idiopathic interstitial pneumonias include: idiopathic pulmonary fibrosis, idiopathic nonspecific insterstitial pneumonia (NSIP), respiratory bronchiolitis-interstitial lung disease, desquamative instersitial pnuemonia, cryptogenic organizing pneumonia and acute interstitial pneumonia (AIP). Interestingly, AIP is rapidly progressive and histologically indistinguishable from ARDS. Diagnosis can be aided by imaging such as CXR and HRCT. For information on the radiographic and pathologic findings, please refer to the article in Current Problems in Diagnostic Radiology. It is also useful to compare prior imaging to assess for rate of change. In this case, a BAL was also performed. And with a negative infectious and rheumatologic evaluation, the patient was diagnosed with idiopathic interstitial pneumonia and treated successfully with steroids.