Fibrous Dysplasia

Fibrous Dysplasia

– dysplastic disorder of bone characterized by presence of trabeculae of immature bone at 1 or many sites
– represents disordered bone maturation & often results in progressive bony deformity that may be associated with pathological #
– presents in 2nd or 3rd decade
– Albright’s syndrome – polyostotic variant associated with precocious puberty & café-au-lait spots

Signs & Symptoms:
– pain with tenderness & swelling at the site of the lesion (monostotic vs polyostotic)

Xrays:
– ‘ground glass’ appearance
– well-defined marginated lesion with rim of sclerotic bone
– expansion, endosteal scalloping & deformity of affected bone
– ‘shepherd’s crook’ – classic deformity of prox. femur arising from bowing of bone & many pathologic #s

Histology:
– collagenous matrix containing proliferating fibroblasts in haphazard pattern
– paucity of osteoblasts surrounding bony trabeculae à distinguishes it from osteofibrous dysplasia

Treatment:
– non-weightbearing skeleton – observation
– weightbearing skeleton – internal fixation & bone grafting
– sarcomatous transformation – occ in polyostotic form