Metastatic osteosarcoma to the liver after treatment for synovial sarcoma:A case report

Metastatic osteosarcoma most commonly affects the lungs and other bones. He patic metastasis at the time of diagnosis is extremely rare. A 14-year-old boy with synovial sarcoma of the left popliteal fossa was treated with surg ical resection, radiotherapy for microscopic residual disease, and 1 year o f chemotherapy (vincristine, cyclophosphamide, dactinomycin, and doxorubici n). Approximately 10 years after the initial diagnosis, a secondary osteosa rcoma developed in the left proximal tibia. Computed tomography at presenta tion showed bilateral pulmonary metastases and large ossified nodules in th e liver that demonstrated abnormal avidity on Tc-99m MDP bone scan indicati ng hepatic metastasis. Despite chemotherapy (cisplatin, ifosfamide, high-do se methotrexate, and dacarbazine), the patient died of progressive disease 4 months after the diagnosis of the second cancer. Hepatic metastasis was f ound at the time of diagnosis of a secondary osteosarcoma and manifested as ossified nodules. The risk of radiation-induced osteosarcoma should always be considered in decisions about treatment for soft-tissue sarcoma.