Polyostotic Fibrous Dysplasia

  • Etiology: focal arrest in normal osteoblastic activity resulting in presence of all components of normal bone with lack of normal differentiation into their mature structures
  • Imaging: multifocal, unilateral, lucent / ground glass lesion in marrow with sclerotic rim
  • Clinical: 20% of fibrous dysplasia is polyostotic, McCune-Albright syndrome (2% of fibrous dysplasia) = polyostotic fibrous dysplasia, precocious puberty, cafe au-lait spots

Radiology Cases of Polyostotic Fibrous Dysplasia

Radiograph of polyostotic fibrous dysplasia
AP radiograph of the femur (above left) shows a metaphyseal lesion that is expansile, lytic in appearance, with a narrow zone of transition and no periosteal new bone that has the appearance of a shepherd’s crook. AP radiograph of the bilateral tibia and fibula (upper right) shows multiple left tibial metaphyseal and diaphyseal lesions that are lytic in appearance with a narrow zone of transition and no periosteal reaction. AP radiograph of the feet (below) shows lesions in the diaphysis of the left first metatarsal and proximal phalanx that are lytic in appearance with a narrow zone of transition and no periosteal new bone.