High-grade surface osteosarcomas.

Nine patients (seven males and two females) had high-grade, ordinary-type osteosarcomas that were juxtacortically located. The ages of these patients ranged from 9 to 62 years at the time of diagnosis. The roentgenographic appearance of these tumors occasionally is similar to that of periosteal osteosarcomas. Histologically, these tumors were indistinguishable from ordinary high-grade intramedullary osteosarcomas. None of the nine tumors had histologic features of parosteal or periosteal osteosarcomas. All nine patients were treated by ablative surgery. Seven patients died of tumor. Because of its poorer prognosis, this tumor should be differentiated from other juxtacortical osteosarcomas.