Utility of high-resolution computed tomography and BAL in cryptogenic organizing pneumonia

Background: Cryptogenic organizing pneumonia (COP) is a rare disease, and its diagnosis requires histological confirmation. The objective of our study was to describe the findings of the thoracic high-resolution computed tomography (HR-CT) and bronchoalveolar lavage (BAL) in patients with confirmed COP and evaluate the complementary diagnostic use of BAL and thoracic HR-CT.

Methods: Patients recorded in the registry of interstitial pulmonary diseases between 1991 and 2008 were located and the COP patients selected.

Results: We identified 21 patients with histological confirmation of COP. The median age was 58.0 ± 15.9 years, and 61.9% of patients were female. The most frequent thoracic HR-CT profile was patchy infiltrate (71.4%), followed by parenchymatous consolidation (42.9%). The most frequent BAL profile was mixed alveolitis (62%) with lymphocyte predominance, a CD4/CD8 index of 0.4 and foamy macrophages. The effectiveness of transbronchial biopsy was 66.6%. The diagnostic utility of Poletti's BAL criteria gives us a specificity of 88.8%, although the sensitivity obtained was low. The specificity of certain HR-CT profiles is 99%. In addition, we observed a complementary use of the HR-CT and the BAL.

Conclusions: The imaging findings and BAL could be useful for patients with appropriate clinical presentation and for those whose transbronchial biopsy is negative or for whom a confirmatory biopsy cannot be performed.