Which is NOT a malignant tumour?

(A) Osteochondroma ]A CLASSIFICATION OF BONE TUMOURS. MODIFIED AFTER REVISED WHO CLASSIFICATION - SCHAJOWICZ (1994)Predominant tissueBenignMalignant* Bone formingOsteomaOsteosarcoma:* central* peripheral* parosteal Osteoid osteomaOsteoblastoma* Cartilage formingChondromaChondrosarcoma: OsteochondromaChondroblastoma* central* peripheral* juxtacortical Chondromyxoid fibroma* clear-cell* mesenchymal* Fibrous tissueFibromaFibrosarcoma Fibromatosis * MixedChondromyxoid fibroma * Giant-cell tumoursBenign osteoclastomaMalignant osteoclastoma* Marrow tumours Ewing's tumour Myeloma* Vascular tissueHaemangiomaAngiosarcoma HaemangiopericytomaHaemangioendotheliomaMalignant haemangiopericytoma* Other connective tissueFibromaFibrosarcomaFibrous histiocytomaMalignant fibrous histiocytomaLipomaLiposarcoma* Other tumoursNeurofibromaAdamantinoma NeurilemmomaChordoma