the series comprises 29 giant cell tumors , most of them malignant or premalignant , 25 cartilaginous tumors ( 12 verified chondrosarcomas and 13 chondromas suspect of malignancy ) , 14 cases of sarcoma , 6 of fibrosarcoma , 4 parosseal sarcomas , 3 osteosarcomas and one chordoma .
C0006826
malignancy
C1261473
sarcomas