Osteosarcoma with skeletal muscle metastasis.

Osteosarcoma usually metastasizes to the lung or the bone, but very rarely to the soft tissue. There have been few reports of osteosarcoma patients with long-term survival after the soft tissue metastasis. We report a case of osteosarcoma in a 18-year-old man, who presented with a solitary skeletal muscle metastasis in the right vastus lateralis as the second relapse of the disease. The patient underwent excision surgery without adjuvant chemotherapy, and remains free of the disease for over 34 months after the surgery.