22 Fibrous Dysplasia of the Skull

Burak Sade and Joung H. Lee

Fig. 22.1 (A) T1-weighted postcontrast FatSat (fat saturation) axial and (B) coronal magnetic resonance images. Note the hyperostotic abnormal bone involving the orbital roof, the posterolateral wall of the orbit, and extending into the infratemporal fossa.

Clinical Presentation

A 15-year-old right-handed boy is referred by a pediatric neurologist because of a right frontal, retroorbital headache not responding to aggressive medical treatment.

Neurologic evaluation is within normal limits.

Magnetic resonance imaging (MRI) scan of the brain is obtained (Fig. 22.1).

Questions

Interpret the MRI scan.

What is your differential diagnosis?

What additional studies would you obtain?

What would be the indications for surgery based on your preoperative diagnosis?

Because of the intractable nature of his headaches, the patient was offered surgery. A right frontotemporal craniotomy was performed with a skull-base approach consisting of extensive extradural removal of the lesion involving the orbital roof and the posterolateral wall of the orbit. The resection was further extended to the inferior orbital fissure inferiorly and foramen ovale posteriorly until normal bone texture was seen at all margins.

Postoperative MRI confirming complete resection of the tumor is shown in Fig. 22.2.

The histology of the tumor was reported as “benign bone and fibrous tissue,” consistent with fibrous dysplasia. At 6-week follow-up, his headaches were significantly improved.
What would be your management goals?
What is the role of radiation therapy in the treatment of fibrous dysplasia?
What is the McCune–Albright syndrome?