Thanks to Alex Heffess MD for the following differentials:
The tree-in-bud sign is nonspecific and an indicator of diseases of the peripheral airways; it can be seen most commonly in infectious processes including Mycobacterium tuberculosis, other mycobacterial, bacterial, viral, parasitic, fungal agents and Pneumocystis pneumonia. This finding is also seen in diffuse panbronchiolitis and congenital disorders such as cystic fibrosis, dyskinetic cilia syndrome, yellow nail syndrome, or congenital immunodeficiency states. Neoplasms such as primary pulmonary lymphoma can demonstrate the tree-in-bud pattern.
Follicular bronchiolitis (connective tissue d/o and immune suppressed.)
Silicosis /coal workers pneumoconiosis
Pulmonary medicine consultation and referral to the Multidisciplinary Pulmonary Nodule Clinic may be helpful. If desired, please contact the clinic coordinator, Diedre Aguiar, on Mount Auburn Pager 6461 or at 617-354-8771.
Crazy paving differential diagnosis includes infection including Pneumocystis, adenocarcinoma, pulmonary alveolar proteinosis, sarcoidosis, nonspecific interstitial pneumonia, organizing pneumonia, drug toxicity, inhalational injury and pulmonary hemorrhage. http://dx.doi.org/10.1148/rg.236035101