PPB unfortunately has the tendency to spread beyond its site of origin in the lung or pleura (lung covering). It certainly often spreads within the chest cavity. It can also spread directly to the diaphragm and to the center area of the chest (the mediastinum, see Definitions/Glossary). PPB can spread through the blood stream to distant organs, especially the bones, liver, and brain.
Metastasis of PPB is found by using various x-ray techniques such as CT scans, MRI scans, or bone scans. Metastasis of PPB is almost never treated by surgery. If one metastasis is seen on a scan, there likely are others which cannot be seen. Chemotherapy or radiation therapy, or both, will be the treatments recommended.