Central high-grade osteosarcoma of bone: Diagnostic and genetic considerations

High-grade central osteosarcoma (OS) is the most common histological variant of OS. Diagnosis requires histological and radiographical examinations. OS is characterized by the presence of osteoid-extracellular matrix. Tumours are treated with neo-adjuvant chemotherapy and limb salvage surgery. Targeted drugs are not yet available for these sarcomas. OS has a remarkably high level of chromosomal alterations. Genetic mutations have been identified for TP53, RB1, CDKN2A, CDK4, MDM2 and CHK2 and may, in some cases, be inherited through the germline. Telomere maintenance is obtained through two different mechanisms, the expression of telomerase enzyme (TERT) or by alternative lengthening of telomeres (ALT). Several genome-wide expression profiling studies are aiming to identify new prognostic markers and targets for therapy.