<prompt> Which one of the following is a malignant bone tumour?Osteoid osteomaChondromaChondrosarcomaOsteochondroma  <response>: C Chondrosarcoma MALIGNANT PRIMARY BONE TUMORS include osteosarcoma, chondrosarcoma, Ewings sarcoma, malignant fibrous histiocytoma, fibrosarcoma, and other sarcoma types. Multiple myeloma is a hematologic cancer which also frequently presents as one or more bone tumors. CLASSIFICATION of BONE TUMOURS: Cartilage tumors Osteochondroma: Chondromas Enchondroma Periosteal chondroma Chondroblastoma Chondromyxoid fibroma Chondrosarcoma Dedifferentiated Mesenchymal Clear cell Periosteal Osteogenic tumors: Osteoid osteoma B, Osteoblastoma Fibrogenic tumors: Desmoplastic fibroma of bone, Fibrosarcoma of bone Fibrohistiocytic tumors: Histiocytoma of bone Ewing sarcomaPrimitive neuroectodermal tumor Giant cell tumors: Giant cell tumor Notochordal tumors: Chordoma Vascular tumors: Haemangioma and related lesions, Angiosarcoma Myogenic, lipogenic, neural and epithelial tumors: Leiomyosarcoma of bone, Lipoma of bone, Adamantinoma and osteofibrous dysplasia Tumors of undefined neoplastic nature: Aneurysmal bone cyst Simple bone cyst; Fibrous dysplasia B; Langerhans cell histiocytosis LCH 