Fibrous Dysplasia
Jan M. Eckermann, MD
Department of Neurosurgery
Definition
• Benign condition in which normal bone is
replaced by fibrous connective tissue due
to a defect in osteoblast differentiation and
maturation
Epidemiology
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Incidence not known
Females > males
No race predilection
Initial symptoms manifest age 3-15
Not heritable
Questionable genetic transformation
Malignant transformation in < 1%
Variations
• Cystic (21%)
- Radiolucency surrounded by solid rim
• Sclerotic (23%)
- Dense and homogenous
• Mixed (56%)
- “Ground glass appearance”
Variations, cont’d
• Monostotic
- Most common
- 25% involve head and neck
• Polyostotic
- 15% of cases
- 50% involve head and neck
Whereyouat?
Images
• Left temporal bone
involvement
Images
• Right temporal bone
lesion
Images
Presentation
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Local pain
Swelling
Abnormal pigmentation
CN compression
Spontaneous scalp hemorrhage
Part of McCune-Albright’s syndrome
McCune-Albright’s Syndrome
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Polyostotic fibrous dysplasia
Café-au-lait spots
Endocrinopathology:
Hyperthyroidism
Precocious puberty in females
Imaging
• Plain radiography is first line
• Computed tomography for complex
regions
Histology
• Fibroblasts within
woven cancellous
bone
Whereyouat?
Differential Diagnosis
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Eosinophilic granuloma
Nonossifying fibroma
Bone hemangioma
Hyperparathyroidism
Paget’s disease
Brown’s tumor
Aneurysmal bone cyst
Treatment
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No available cure
Curettage
Cranioplasty
Calcitonin
The One Slide To Remember
• Genetic, non-heritable disorder
• <1% transformation to malignancy
• Treatment is curretage or cranioplasty
Whereyouat?
References
• Greenberg, M. Handbook of Neurosurgery
6th Edition. Thieme: New York 2006
• Kaye AH, Black P McL. Operative
Neurosurgery Vol 2. Harcourt Publishing:
New York 2000
• Dal Cin P, Sciot R, Spelenberg F, et al.
Chromosome Aberration in Fibrous
Dysplasia. Cancer Genet Cytegent 1994
Oct15;77(2) 114-7