Chordoma

Definition

Chordoma is a rare malignant bone tumor that typically arises from remnants of the notochord, an important structure in the early embryonic development of the spine. The notochord usually disappears as the spine develops, but in some cases, small remnants of the notochord can persist, and these remnants can later give rise to a chordoma. Chordomas typically occur in the spine or the base of the skull, and they can cause pain and neurological symptoms due to compression of adjacent tissues.

Epidemiology

Chordoma is the fourth most common primary bone tumor and accounts for about 3% of all primary bone tumors and 20% of spinal tumors. The overall incidence is approximately 1 per 1,000,000 individuals; there are thus about 300 new cases annually in the United States. Although chordomas occur almost exclusively in the axial skeleton due to their notochordal origin, rare cases have been reported in the appendicular skeleton and soft tissues. The sacrum and coccyx are the most common locations (~50% of cases), followed by the spheno-occipital region (~35%) and the remainder in the cervical, thoracic and lumbar regions.

The incidence of chordoma increases with age, with the median age at diagnosis being 57 years old. Spheno-occipital tumors are more common in younger patients, while sacral tumors are more common in older age groups. The majority of patients are white, and males are affected more often than females.