Solitary Pulmonary Lesion in Patients With History of Malignancy: Primary Lung Cancer or Metastatic Cancer?

How to manage solitary pulmonary nodules appearing after treatment of a prior malignancy remains a clinical challenge.  The authors found that such patients most often had intrapulmonary metastases and less often had new lung cancers.  Factors associated with new lung cancers included spiculated nodules, absence of nodal involvement with prior cancers, and prior cancers from other than head/neck and genitourinary sources.