Benign osteoblastoma of vertebral column and skull. Report of two cases.

Osteoblastoma of the spine is a rare but important cause of back pain and the sciatica syndrome in young adults. Osteoblastoma of the skull is rare and the involvement of the orbital roof is very unusual. Clinical complaints and physical examination are not specific enough to provide a lead to the diagnosis. Bone scans and computerized tomography scans should be performed in all cases, to show the extent of vertebrae or calvarium infiltration by the tumor. To prevent recurrence and malignant transformation, the tumor should be completely removed whenever possible. If tumor excision is incomplete, a continuous follow-up is necessary to detect any recurrence or malignant transformation, which normally appears 5-10 years after the first operation (in one of our cases 7 years later).