Diffuse pulmonary nodules

Diffuse pulmonary nodules are usually seen as multiple pulmonary nodular opacifications on a HRCT chest scan. They can signify disease processes affecting either the interstitium or the airspace. They can range from a few millimeters to up to 1 cm and when very small and numerous there can be some overlap with the term miliary nodules. They can arise from a vast number of pathological entities.

Differential diagnosis

Differentials to be considered include:

• sarcoidosis

• silicosis

• respiratory bronchiolitis (infective or non-infective)

• other forms of infection                                      

  • tuberculosis: bronchogenic disseminated tuberculosis ²

  • non-tuberculous mycobacterial infection

  • other infective bronchiolitides

    • pulmonary haemophilus influenzae infection

    • pulmonary mycoplasma pneumoniae infection

  • fungal infections such as forms of aspergillus infection

  • septic emboli from infective endocarditis or infected tube 

• small airway disease

• hypersensitivity pneumonitis

• malignant entities ​

  • nodular metastases

  • adenocarcinoma

  • forms of pulmonary lymphoma

  • Kaposi sarcoma

• other miscellaneous conditions​

  • granulomatosis with polyangiitis

  • alveolar microlithiasis: very dense

  • diffuse panbronchiolitis

  • diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH)

  • pulmonary amyloidosis: nodular forms ²

Related articles

• approach to diffuse pulmonary nodules

• solitary pulmonary nodule