[Pedicle agenesis in the cervical spine]

Congenital absence of a cervical pedicle is rare, and because of the associated enlargement of the intervertebral foramen, may be confused with a "dumbbell" tumour. A recent observation of this anomaly has prompted this report. Based on the findings of 29 reported cases in the literature, the characteristic radiological features of the abnormality are described and the differential diagnosis as well as the clinical implications of this disorder are discussed.