Osteosarcoma with multiple skeletal metastases. A case of "nonstochastic" metastasis.

Osteosarcoma of the thoracic spine developed in a 15-year-old Japanese boy. After his first admission with paralysis, multiple skeletal metastases were demonstrated in the absence of pulmonary metastasis. This rare condition may possibly be considered as a unicentric osteosarcoma with bone metastases, since there were no precursor lesions or history of exposure to radioactive materials or chemical agents. These multiple lesions may be an example of so-called "organ-specific metastasis," although this "nonstochastic" process is rare.