Classic high-grade osteosarcoma is a highly malignant spindle-cell
sarcoma of bone in which the malignant cells produce osteoid1. It is the most common primary malignant
tumor of bone, excluding myeloma, and is the third most common malignant
disease in adolescence after leukemia and lymphoma. However, it
is still a rare tumor with only 1000 new cases per year in the United States.
There appears to be no racial or ethnic influence associated with
its incidence2. However, an increased
prevalence has been noted in families affected with the Li-Fraumeni
syndrome3 and in patients who
have had retinoblastoma4 (a 40% prevalence
in those with bilateral disease), have undergone radiation therapy5, or have Paget disease6.