Miliary or Small Nodular Pattern
A determination of the distribution of the nodules will aid in refining the differential:Diffuse (Random) Pattern:
Miliary tuberculosisMetastatic disease
Synthetic marijuana inhalation {AJR 2015; Berkowitz EA, et al. 204: 750-757
Perilymphatic Pattern:
SarcoidLymphangitic Metastatses
Silicosis
Centrilobular Pattern:
Extrinsic allergic alveolitis (Nodules are ill-defined)Vascular disorders (Pulmonary edema [look for interstitial thickening], Vasculitis)
Centrilobular with Tree-in-bud Pattern: Small airways disease
Infectious bronchiolitis (Bronchopneumonia, MAC, TB)Bronchial Disease (Bronchiolitis/ Diffuse panbronchiolitis, Cystic Fibrosis)
Lymphatic disease (Can produce centrilobular densities, but look for interstitial/perilymphatic abnormalities as well)
- Lymphangectic carcinomatosis
- Sarcoid
- Langerhans Cell Histiocytosis
