Osteogenic sarcoma (osteosarcoma) in the elderly: tumor delineation and predisposing conditions.

Osteogenic sarcoma (OS), the most common primary bone cancer, is conventionally a primary intramedullary (conventional OS) high-grade malignant tumor characterized by malignant cells forming immature bone or osteoid. The age distribution data for primary bone sarcomas are bimodal. OS is largely a disease of the young but about one-third of OS occurs in patients over 40 years of age. Thus, though considered as rare occurrences, bone tumors occur also in the geriatric population. In this report, tumor delineation and the significance of predisposing conditions to the occurrence of OS are reviewed.