Value of MRI in the diagnosis of non-clival, non-sacral chordoma

Objective: To determine the MR features of non-sacral, nonclival chordoma and to describe a MR prototype of the lesion. Design and patients: We reviewed the MR findings of 10 patients with a histologically proven chordoma (6 cervical spine, I thoracic spine, 3 lumbar spine). There were three female and seven male patients. Age ranged from 12 to 66 years with a mean age of 44.6 years. The MR images were reviewed for signal intensity (SI) and morphology. Results: All lesions showed a soft tissue extension spanning several vertebral segments. Most of the lesions exhibited a so-called collar button appearance (sagittal images). Two cases of cervical chordoma displayed a "dumbbell morphology" (axial images) or "mushroom" appearance without bone involvement and with enlargement of the neuroforamen mimicking a neurogenic tumor. Although the region of the nucleus pulposus is the last part of the fetal notochord in the adult to involute, disks were surprisingly spared in all patients. Eight of 10 patients showed heterogeneous SI on all sequences. The overall SI of all lesions was isointense or slightly higher than that of muscle on T1-weighted images. All lesions exhibited high SI on T2-weighted images. After gadolinium contrast administration there was a moderate enhancement in most cases. Conclusions: Although the SI on MR imaging is not specific, chordoma should be considered when a destructive lesion of a vertebral body is associated with a soft tissue mass with a collar button or mushroom appearance and dumbbell morphology, spanning several vertebral segments and sparing the disk(s).