Computed tomography of axial chordomas.

Preoperative computed tomography (CT) of 19 patients with axial chordomas was reviewed. These tumors characteristically feature a well-demarcated paraspinal soft tissue mass which is usually anterolaterally situated and has a homogeneous density comparable to that of muscle. The soft tissue component is disproportionately large compared to the area of bony involvement. Lytic or mixed vertebral lesions were noted. Amorphous calcifications that tended to occur at the periphery of the tumor were particularly common (89%) in chordomas of the sacrum. Epidural extension of tumor was noted in all spinal cases. Although it appears that CT studies will generally not enable a specific diagnosis of chordoma, the above features should alert the examiner to the possibility of this tumor.