Study design: Case report.
Objective: To describe a case of monostotic fibrous dysplasia of the first cervical vertebra.
Summary of background data: Fibrous dysplasia is a disorder of bone development of unknown etiology in which cancellous bone is replaced with fibrous tissue, resulting in expansion of the bone. The disease presents in either a monostotic or polyostotic form. Although fibrous dysplasia can involve any bone in the body, vertebral involvement is quite unusual.
Methods: A case of monostotic fibrous dysplasia of the first cervical vertebra is presented.
Results: A 53 year-old woman presented with a 1-month history of occipito-cervicalgia associated with great restriction of neck movements. Computed tomography and magnetic resonance imaging revealed an expansile, destructive lesion involving the right lateral mass of the first cervical vertebra, without involvement of the spinal cord. She was submitted to surgery and the lesion was removed. Microscopic examination was consistent with the diagnosis of fibrous dysplasia. Four years after surgery there was no clinical or imagiological recurrence.
Conclusion: Although there are descriptions of vertebral fibrous dysplasia, this is the 12th case of monostotic fibrous dysplasia of the cervical spine described in the literature. Computed tomography and magnetic resonance imaging were essential for making the preoperative diagnosis.