Osteofibrous dysplasia.

Osteofibrous dysplasia is a benign, slowly progressive lesion which generally involves one tibia of an infant or young child, and presents as anterior bowing associated with a painless mass. Surgical intervention is usually not indicated but, when carried out, recurrences are common. Osteofibrous dysplasia is readily distinguished histologically from fibrous dysplasia by fibrous stroma, containing bone trabeculae which are rimmed by osteoblasts, and by a "zonal architecture." The radiographic appearance is that of a benign, lucent, intracortical lesion which is expansile and produces bowing of the tibia. Four patients with this condition are presented.