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

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.

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

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.

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.