Chest ImagingBronchiolitis obliterans with intraluminal polyps
a common reparative reaction that occurs in a number of settings (Table 1).
Bronchiolitis obliterans with intraluminal polyps, Table 1. Causes of bronchiolitis obliterans with intraluminal polyps.
| |
| Reparative reaction with: | |
| - viral, bacterial or fungal pneumonia | |
| - bone marrow and lung transplantation | |
| - connective tissue disease | |
| - drug reaction | |
| - irradiation | |
| - chronic eosinophilic pneumonia | |
| Idiopathic | |
Histologically, polypoid endobronchial connective tissue masses composed of myxoid fibroblastic tissue appear to float freely within a bronchiole or be only focally attached to the wall. The fibroblastic proliferation is continuous with a similar process in the more distal airspaces (organizing pneumonia). When patchy organizing pneumonia is present, the two lesions are combined in the name bronchiolitis obliterans organizing pneumonia (BOOP). Idiopathic BOOP is considered as an infiltrative lung disease. In the United Kingdom it is called cryptogenic organizing pneumonia.
The radiological changes in bronchiolitis obliterans with intraluminal polyps depend on the presence and extent of organizing pneumonia associated with bronchiolar lesions.
When organizing pneumonia is present and the main radiological findings include unilateral or bilateral areas of airspace consolidation (BOOP pattern). When organizing pneumonia is absent, the chest radiograph is normal or shows nonspecific findings such as nodular opacities and bronchial wall thickening. On high resolution CT scans, small centrilobular nodular and linear opacities may be seen with a patchy distribution. Decreased lung attenuation with mosaic perfusion and expiratory air trapping may also be present.
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