Surface osteosarcoma: 2 case reports.

Surface osteosarcoma of the jaw bone is extremely rare, and it differs from the central type in its clinicopathologic features. This type of osteosarcoma generally shows low-grade malignancy, grows slowly, metastasizes less often, and the prognosis is better than that of the central type. We report 2 cases of surface osteosarcoma of the jaw bone, and discuss some clinical important issues.