Bronchiolitis Obliterans - Diagnosis

Diagnosis

Bronchiolitis obliterans is often misdiagnosed as asthma, bronchitis, emphysema, or pneumonia.

Diagnosis may include the following tests:

• Chest X-rays tests.
• Diffusing capacity of the lung (DLCO) tests are usually normal.
• Spirometry tests show fixed airway obstructions and sometimes restriction. FEV1/FVC may therefore be <75%.
• Lung volume tests may show hyperinflation (excessive air in lungs caused by air trapping).
• High-resolution computerized tomography scans of the chest at full inspiration and expiration may reveal heterogeneous air trapping on the expiratory view as well as haziness and thickened airway walls.
• Lung biopsies may reveal evidence of constrictive bronchiolitis obliterans (i.e., severe narrowing or complete obstruction of the small airways). An open lung biopsy, such as by thoracoscopy, is more likely to be diagnostic than a transbronchial biopsy. Special processing, staining, and review of multiple tissue sections may be necessary for a diagnosis.