centrilobular lung nodules
Centrilobular lung nodules refer to an HRCT chest imaging descriptor for small 5-10 mm lung nodules which are anatomically located centrally within secondary pulmonary lobules. The term is applied on the basis of location of the nodule and not its morphology that is they may be well defined or poorly defined ground glass in appearance. If extremely small they are termed centrilobular micronodules.
Centrilobular nodules can be observed in a wide variety of lung pathology. They are usually seen with a bronchiolitis (i.e with bronchiolar or peribronchiolar abnormalities). Specific conditions include:
- infection with endobronchial spread
- bronchoalveolar carcinoma with airway spread
- subacute hypersensitivity pneumonitis
- respiratory bronchiolitis interstitial lung disease (RB-ILD)
- pulmonary vasculitides
When centrilobular nodules are interspersed with linear and branching densities, it is then termed a tree-in-bud pattern.
Centrilobular nodules are typically around the small airways and spare the subpleural surfaces. They are typically at least 5-10 mm away from the pleural surfaces .