Juxtacortical osteosarcoma. A distinct malignant bone neoplasm.

: The purpose of this report is the study of a malignant bone tumor of similar histological picture with conventional (intramedullary) osteosarcoma. Contributing factors in the study of juxtacortical osteosarcoma are the clinical, X-ray and histologic pictures. A case of parosteal osteosarcoma in a 28-year-old male is reported. In conjuction with X-ray findings we review the histological characteristics of the tumor through serial sections of the peripheral, central and parosteal parts and the findings are described in detail. In addition to the histological findings, differential diagnosis and prognosis are also discussed. From the general study of the tumor it has been shown that juxtacortical osteogenic sarcoma behaves differently in contrast to classic osteosarcoma, depending on the degree of differentiation of the tumor.