FIBROUS DYSPLASIA AND OSTEOFIBROUS DYSPLA SIA

Fibrous and osteofibrous dysplasia are benign lesions of the bone invo lving single bones as monostotic or multiple bones as polyostotic form s. When the patient is in the growth phase, the lesions, which are usu ally asymptomatic initially, may lead to deformities with typical bowi ng of the proximal femur (''shepherd's crook'') and fractures. It is i mportant to recognize osteofibrous dysplasia of the tibia and fibula, where any surgical measures, even a small biopsy, may activate the pro cess and cause the lesion to grow, although it may spontaneously rest around puberty. Polyostotic fibrous dysplasia may rarely be associated with areas of cutaneous pigmentation and endocrine disturbances, espe cially precocious puberty (McCune-Albright syndrome).