DDX of solitary solid lung mass

Approach to the DDX of a solitary solid lung mass:

  • Solitary solid lung masses are often noted incidentally on CXR
  • In the appropriate clinical setting of infection, round pneumonia may be presumed and treated. A followup CXR should be obtained 2 weeks after end of treatment to verify resolution of the mass. If the mass has not resolved, chest CT is indicated
  • If a lung mass is calcified it can be presumed to be a granuloma, most likely from histoplasmosis or tuberculosis
  • If a patient has a malignancy and a new lung mass, a short interval followup CT can be obtained in 2 weeks to exclude infection as the cause of the mass
  • Pleuropulmonary blastoma is the lung mass that most commonly fills the entire hemithorax