Known case of osteosarcoma with pulmonary metastasis and pleural effusion. 
Treated metastases, osteosarcomas and chondrosarcomas may also contain calcified densities.

In the pediatric population, the most common primaries for pulmonary metastases are rhabdomyosarcoma, osteosarcoma, Wilms tumor, Ewing sarcoma and neuroblastoma.