A sarcoma in which the predominant cell type is a malignant fibroblast.
In the skull, it appears as a radiolucency or bone defect.
The malignant transformation from a chordoma into fibrosarcoma or malignant fibrous histiocytoma is rare.
The malignant transformation of a fibrous dysplasia occurs in < 1% of cases 1) typically to osteosarcoma, but other sarcomas are possible (fibrosarcoma, chondrosarcoma…)