Cutaneous metastasis of osteosarcoma.

Cutaneous metastases of solid tumors have been reported with a frequency that ranges from 0.7% to 4.4% with recent studies reporting 9% and 10%. Osteosarcomas seldom metastasize to the skin. The most frequent metastatic sites are to the lungs, bones, and kidneys. We report 2 cases of osteosarcoma that metastasized to the skin. A 75-year-old patient with known osteosarcoma of the tibia developed cutaneous nodules overlying the site of the primary tumor. A 46-year-old woman with a history of osteosarcoma of the knee developed a nodule on her scalp. Histologic examination of both lesions revealed metastatic osteosarcoma. This is a rare event that, to our knowledge, has previously only been reported 6 times.