Unusual late extrapulmonary metastasis in osteosarcoma.

The major site of metastasis from osteosarcoma is the lung, and over 90% of fatalities in patients with this disease die from pulmonary metastases. Extrapulmonary disease is developing in an increasing proportion of patients, usually after pulmonary metastasis. This study reports three cases of patients with osteosarcoma that metastasized to the brain, mediastinum, intramuscular site, and pelvic cavity. The physician must be aware that extrapulmonary metastases may be present at the time a pulmonary metastasis becomes evident.