Demographics, presentation, and diagnosis

Chordomas and chondrosarcomas are rare bone cancers that share many clinicoradiological similarities. Nevertheless, they are distinct pathological entities that markedly differ regarding their origin, history, and prognosis. Chordomas represent 3% of primary bone tumors, develop from remnants of the primitive notochord, and may affect the skull base and any part of the spine. Chondrosarcomas represent 7% of primary bone tumors, appear to develop from cartilaginous rests during the process of ossification, and most commonly involve the long bones of the appendicular skeleton, although they may also affect the axial skeleton. Given the importance of distinguishing between these neoplasms for proper management, this chapter will review demographic and clinical data emphasizing their differences.