Presentation
65-year-old woman presented to the emergency room after a tumble where she had hit her head. A cerebral and craniofacial CT scan was requested to exclude intracranial hemorrhage and fractures.
Patient Data
CT scan of craniofacial bones showed a process with sclerotic margins and a ground-glass center that stretched from the right ethmoidal sinus into the right sphenoidal sinus. A mild, ground-glass appearance of the basal skull bone structure was also observed.
Case Discussion
The findings were concluded to be craniofacial fibrous dysplasia.
Fibrous dysplasia is a benign, slow-growing dysplastic process of altered bone formation, characterized by the replacement of normal bone by fibrous bone tissue that can involve a single bone (monostotic) or many bones (polyostotic) 1-3. The most common sites involved are the femur (most common), ribs and skull 4. Craniofacial involvement has been reported in about 10% to 25% of monostotic cases and in about 50% of polyostotic cases 5-7. Polyostotic fibrous dysplasia can present with other disorders, the most common being McCune-Albright syndrome 7.
Radiographic features differ with various stages of disease, early lesions are radiolucent but calcify later on, aquiring a “ground-glass” appearance. Critical to the diagnosis is that fibrous dysplasia does not have well-defined margins, ergo the lesions blend into the adjacent normal osseous tissue 8.