Fibrous DysplasiaFibrous Dysplasia

Jan M. Eckermann, MDJan M. Eckermann, MD

Department of NeurosurgeryDepartment of Neurosurgery

DefinitionDefinition

• Benign condition in which normal bone is replaced by fibrous connective tissue due to a defect in osteoblast differentiation and maturation

EpidemiologyEpidemiology

• Incidence not known

• Females > males

• No race predilection

• Initial symptoms manifest age 3-15

• Not heritable

• Questionable genetic transformation

• Malignant transformation in < 1%

VariationsVariations

• Cystic (21%)- Radiolucency surrounded by solid rim

• Sclerotic (23%)- Dense and homogenous

• Mixed (56%)- “Ground glass appearance”

Variations, cont’dVariations, cont’d

• Monostotic- Most common- 25% involve head and neck

• Polyostotic- 15% of cases- 50% involve head and neck

Whereyouat?Whereyouat?

ImagesImages

• Left temporal bone involvement

ImagesImages

• Right temporal bone lesion

ImagesImages

PresentationPresentation

• Local pain

• Swelling

• Abnormal pigmentation

• CN compression

• Spontaneous scalp hemorrhage

• Part of McCune-Albright’s syndrome

McCune-Albright’s SyndromeMcCune-Albright’s Syndrome

• Polyostotic fibrous dysplasia

• Café-au-lait spots

• Endocrinopathology:

- Hyperthyroidism

- Precocious puberty in females

ImagingImaging

• Plain radiography is first line

• Computed tomography for complex regions

HistologyHistology

• Fibroblasts within woven cancellous bone

Whereyouat?Whereyouat?

Differential DiagnosisDifferential Diagnosis

• Eosinophilic granuloma

• Nonossifying fibroma

• Bone hemangioma

• Hyperparathyroidism

• Paget’s disease

• Brown’s tumor

• Aneurysmal bone cyst

TreatmentTreatment

• No available cure

• Curettage

• Cranioplasty

• Calcitonin

The One Slide To RememberThe One Slide To Remember

• Genetic, non-heritable disorder

• <1% transformation to malignancy

• Treatment is curretage or cranioplasty

Whereyouat?Whereyouat?

ReferencesReferences

• 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