DDX of pneumonia in immune suppressed patients

Approach to the DDX of pneumonia in immune suppressed patients:

  • Pneumocystis jiroveci pneumonia should be suspected in a patient with fine reticular infiltrates, but Pneumocystis jiroveci pneumonia has an extremely variable imaging appearance
  • Lymphocytic interstitial pneumonitis should be suspected in a patient with nodular interstitial infiltrates
  • Invasive aspergillosis should be suspected in a patient with a mass-like lesion, CT likely will confirm the diagnosis