“…Twenty-three cases were de novo cranial osteosarcomas: 14 calvarial tumors and 9 tumors of the skull base. 4,9,12,15,18,22,24,27,33,41,42,45,46,50,52,56,58,62,64,66 Nine cases of cranial osteosarcoma secondary to prior therapeutic radiation have been reported in children, 2 involving tumors of the skull base and 7 involving tumors of the calvaria. 8,15,16,33,39,54,55 Four cases of metastatic cranial osteosarcoma have been reported: 3 cases of metastatic cranial osteosarcoma from primary long bone tumors (2 involving the calvaria and 1 involving the cranial base) 40,42,44 and 1 case of metastatic osteosarcoma to the cranial base with a history of radiotherapy, in the context of multifocal disease.…”