Discussion :
METASTASIS TO LUNG

Pulmonary metastases occur in 30% of all malignancies; mostly hematogenous Age:>50 years (in 87%)

Incidence of pulmonary metastases :
mnemonic: "CHEST"
-Choriocarcinoma 60%
-Hypernephroma / Wilms tumor 30 / 20%
-Ewing sarcoma18%
-Sarcoma (rhabdomyo- / osteosarcoma)21 / 15%
-Testicular tumor12%
-multiple nodules (in 75%) of varying sizes (most typical), 82% subpleural
-fine micronodular pattern: highly vascular tumor (renal cell, breast, thyroid, prostate carcinoma, bone sarcoma, choriocarcinoma) -pneumothorax (2%): especially in children with bone tumors 

CT:

-noncalcified multiple (>10) round lesions >2.5 cm likely to be metastatic