Giant cell tumour in a vertebra affected by Paget's disease of bone.

A case of giant cell tumor in a vertebra affected by Paget's disease of bone is presented. This lesion, which is quite rare, has usually been observed in the bones of the skull and face, and is benign. It is probably hyperplastic rather than neoplastic in nature. Radiotherapy is contraindicated, since bone affected by osteitis deformans may possibly become malignant.