Primary central (medullary) fibrosarcoma of bone.

Eighty cases of primary fibrosarcoma of bone from the Rizzoli Institute are reviewed. There was a slight male predominance with a wide patient age distribution. Roentgenologically, low grade fibrosarcomas had generally well-defined margins and a "soap-bubble" appearance. High grade tumors appeared permeative and more aggressive. Histologically, the majority of tumors were high grade (3 and 4). Prognosis correlated well with the grade of the tumor. The 10-year survival rate was 83% for low grade sarcomas and 34% for high grade tumors. Local recurrence was a bad prognostic sign.