Polyostotic fibrous dysplasia; a case report.

Fibrous dysplasia is a condition leading to abnormal differentiation of osteoblasts which leads to replacement of normal bone with fibrous stroma [1-3]. It may involve single bone (monostotic) or multiple bones (polyostotic). It may affect any bone however; skull and ribs are the commonest [2,4-6]. It is usually asymptomatic and is an incidental finding. It may become symptomatic when complicated by pathologic fracture or malignant change. It may be associated with aneurysmal bone cysts [6-12]. The mechanism of occurrence of ABC with Fibrous dysplasia is not known but it may be said that there may be a secondary disruption of osseous supply caused by the fibrous dysplasia leading to ABC. This association of ABC with fibrous dysplasia may lead to rapidly increase in growth which may be confused with malignant change [5,10]. We report a case of polyostotic Fibrous dysplasia in a 26-year-old lady showing the characteristic changes.