How should fibrous dysplasia of the frontal bone presenting with headache be evaluated and managed?

Fibrous Dysplasia of the Frontal Bone with Headache

For fibrous dysplasia of the frontal bone presenting with headache, obtain immediate non-contrast CT of the skull to assess for posterior table involvement, intracranial extension, and complications requiring neurosurgical intervention, followed by conservative management with bisphosphonates for symptom relief in uncomplicated cases. 1, 2

Initial Diagnostic Evaluation

Imaging is mandatory to characterize the lesion and exclude complications:

• Non-contrast CT of the skull is the primary imaging modality to evaluate the extent of bony involvement, assess posterior table integrity, and identify intracranial complications 1, 3
• Look specifically for posterior table fractures/involvement, which implies potential dural rupture and communication with the anterior cranial fossa 1
• Assess for pneumocephalus, CSF leak, nasofrontal duct obstruction, and mass effect on intracranial structures 1, 4
• MRI brain with contrast should be added if there is concern for intracranial extension, venous compression, or neurologic symptoms beyond headache 5, 4

Additional imaging considerations:

• Bone scintigraphy with SPECT can confirm increased bone metabolism and help differentiate monostotic from polyostotic disease 2, 6
• MRI is superior for detecting venous compression (sigmoid sinus, other dural sinuses) which can cause intracranial hypertension and severe headache 4

Clinical Assessment Priorities

Evaluate for complications requiring urgent intervention:

• Intracranial hypertension signs: severe or rapidly worsening headache, vomiting, altered consciousness, papilledema 1, 4
• Visual symptoms: proptosis, visual acuity loss, diplopia, or epiphora suggesting orbital involvement 7, 8
• Cranial nerve deficits: anosmia, hearing loss, facial pain, or other focal neurologic findings 7, 8
• Sinus complications: chronic sinusitis, mucocele formation, or recurrent infections 1

Management Algorithm

For Uncomplicated Cases (No Posterior Table Involvement, No Neurologic Deficits):

Conservative medical management is first-line:

• Bisphosphonates (pamidronate IV) are the primary treatment for symptomatic relief of headache and bone pain 2, 8
• 3 of 5 patients treated with pamidronate showed favorable evolution with resolution of headache at 1-6 months 8
• NSAIDs (ibuprofen or naproxen) for additional pain control during initial treatment 9
• Follow-up CT at 1 year to document stability and absence of progression 2

For Complicated Cases Requiring Surgery:

Neurosurgical intervention is indicated when:

• Posterior table involvement with dural injury or CSF leak requires bifrontal craniotomy with cranialization or obliteration of the frontal sinus 1
• Progressive visual deterioration, severe proptosis, or cranial nerve compression necessitates decompression 7
• Venous compression causing intracranial hypertension may require endovascular stenting 4
• Refractory symptoms despite medical management in experienced surgical hands 2, 7

Surgical options include:

• Total excision for accessible lesions (sphenoid wing involvement) 7
• Partial excision with autoclaving, remodeling, and replacement for fronto-orbital disease 7
• Decompression procedures for optic nerve or other neural compression 7

Critical Pitfalls to Avoid

Do not overtreate: Most patients with fibrous dysplasia respond to conservative management, and aggressive surgery should be reserved for true complications 2

Do not delay imaging in red flag scenarios: Rapidly worsening headache, vomiting, or altered consciousness requires immediate CT to exclude intracranial hemorrhage or acute venous compression 1, 4

Do not perform biopsy routinely: In the absence of complications and with characteristic imaging findings, tissue diagnosis is unnecessary and risks triggering disease activity 2

Monitor for late complications: Even stable lesions can develop mucocele formation, osteomyelitis, chronic sinusitis, or late CSF leak requiring long-term surveillance 1

Prognosis and Follow-Up

• Overall surgical outcome is good with no mortality in contemporary series, though recurrent complications (extradural hematoma) can occur 7
• Conservative management with bisphosphonates provides symptom resolution in the majority of uncomplicated cases 2, 8
• Annual imaging surveillance is appropriate for stable lesions without progression 2
• Sarcomatous transformation is exceptional but should be considered if rapid growth or changing characteristics occur 8