MDM2 and chondrosarcoma: The p53/mdm2 pathway appears to be involved in 40–50% of chondrosarcomas and correlated to aggressive behavior (25) but there is no agreement on the cut-off level for positivity, and we did not find any correlation to histological grade, where eight of 25 (32%) exhibited nuclear positivity for mdm-2 in 2–40% of tumor cells.