Imaging findings of pulmonary metastases
Solitary or multiple pulmonary and endobronchial nodules or masses are often seen, which may be ill-defined or well-circumscribed, ground glass or solid in attenuation, and often associated with metastases at other thoracic or extrathoracic anatomic locations. Depending on the underlying primary malignancy, the lesions may be homogeneous or heterogeneous with cystic, necrotic, calcific, or hemorrhagic change, and they may vary in size from very small (miliary) nodules to very large “cannonball” masses. Pneumothorax is often associated with pulmonary metastatic disease from osteogenic sarcoma. Overall, the lungs are an extremely common site of metastatic disease.