Post-Paget osteosarcomas of the skull. Remarks on five cases.

We report our experience with 5 cases of post-Paget osteosarcoma of the skull, a rare lesion of the neurocranium. Four patients were treated by surgery and radiotherapy and one by surgery alone. Two patients received chemotherapy. Histologically, the tumor was found to be an osteosarcoma, fibroblastic in 2 cases, mixed in 2, and osteoblastic in 1. Combined treatment (surgery, radiotherapy and chemotherapy) positively influenced survival (median survival, 6 months). The prognosis for post-Paget osteosarcomas of the skull seems to be worse than for primary sarcomas, probably due to their intense vascularization. This facilitates the spread of tumor cells to other organs (as observed in our cases) and reduces the reduced effectiveness of chemotherapy. Although the latter lengthens survival and reduces the incidence of metastases, it is not as efficacious as in primary sarcomas.