Chordoma : Introduction
Introduction: Chordoma is a rare but aggressive primary bone tumor that arises from notochordal remnants in the axial skeleton. It accounts for 1% to 4% of all bone malignancies, 20% of all primary spine tumors, and 0.5% of all intracranial neoplasms. Chordoma occurs at all ages but is most often seen in the 5th and 6th decades of life. Individuals under the age of 20 yrs. account for only 5% of cases. It is more common in males (M:F = 3:2). Male predominance is quite striking for sacrococcygeal tumors. Sites: The tumor almost always involves the axial skeleton. The predominant sites are fused segments like sacrococcyx (50% of cases) and clivus (at the base of skull near the spheno-occipital synchondrosis, anterior to foramen magnum; 35% of cases). Mobile spine accounts for 15% of cases. Within the spine, the frequency of involvement of segments is as follows: cervical > lumbar > thoracic. Sacrococcygeal tumors are more common in adults, whereas base of skull is a more frequently involved location in children and adolescents. Rare extra-axial chordomas have been reported in the head and neck region, including nasopharynx, paranasal sinuses, lateral nasal wall, oropharynx, and soft tissues of the neck. Slide courtesy of Piero Picci, M.D., Director, Laboratory of Experimental Oncology, Instituto Ortopedico Rizzoli, Bologna, Italy. Used with permission.