Isolated subcutaneous metastasis of osteosarcoma 5 years after initial diagnosis

The pediatric malignancies most likely to metastasize to the skin are neuroblastoma, leukemia, and rhabdomyosarcoma. Cutaneous and subcutaneous metastases from osteosarcoma are extremely rare, with only a few cases reported in pediatric patients with multifocal synchronous osteosarcoma. We describe the case of a 19-year-old woman with a single subcutaneous nodule of the abdominal wall that, on histologic evaluation, proved to be a metastatic high-grade osteosarcoma 5 years after her initial diagnosis.