Case of the Week: April 3-April 10, 2003

History: 17 year old MVC trauma patient.

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Case Details

Answer

Diagnosis: DIAGNOSIS: Fibrous Dysplasia

  • Unknown etiology

  • Osteoblasts fail to undergo normal morphologic differentiation and maturation

  • Cartilaginous islands or nodules present in 10% - not to be mistaken for chondrosarcoma

Other Names Used:

  • Fibrous osteodystrophy

  • Osteodystrophia fibrosa

  • Osteitis fibrosa disseminata

  • McCune Albright Syndrome

    • Polyostotic fibrous dysplasia

    • Café-au-lait spots

    • Precocious puberty

Types

Monostotic form 70-80%

Polyostotic form 20-30%

Monostotic Fibrous Dysplasia

  • Incidental finding

  • May present with pathological fracture

Polyostotic Fibrous Dysplasia

  • Pain

  • Deformity

  • In children - can present with limp

  • Café-au-lait spots - 50%

  • Irregular borders - Coast of Maine

  • Smooth - Coast of California - NF

Bones Involved:

  • Skull

  • Facial Bones

  • Ribs

  • Pelvis

  • Femur

  • Tibia

Imaging Findings:

  • Ground glass appearance

  • Endosteal scalloping

  • Blown-out appearance

  • Shepherd's crook deformity of proximal femur

  • Bone scan - hot

  • MR should not be used to differentiate from other bony entities

Differential Diagnosis:

  • Paget disease

  • Neurofibromatosis

  • Hyperparathyroidism

  • Metastatic tumor

  • Osteomyelitis

  • EG

  • Osteofibrous dysplasia 

    • Tibia

    • < 10 years of age

    • Spontaneous regression

Prognosis:

  • Do not progress beyond puberty

  • Surgery:

    • <1% malignant degeneration

      • osteosarcoma

      • fibrosarcoma

      • chondrosarcoma

  • May occur with Aneurysmal Bone Cyst

Correct answers by users

VCU Resident
Radiology Pediatrics
Others
VCU Department of Pediatric Radiology Virginia Commonwealth University VCU Medical Center