Osteofibrous dysplasia of the ulna

We experienced two patients with osteofibrous dysplasia of the ulna. Both of them showed typical radiographic findings of osteofibrous dysplasia, except for location. One patient underwent surgery at the age of 15 years to confirm the diagnosis histologically. Although the tumor recurred 5 months after the surgery, expansion of the lesion seemed to cease at the age of 25 years. In the other patient, the natural course was observed. The tumor showed a tendency toward spontaneous regression at the age of 11 years. Therefore, the nature of osteofibrous dysplasia in the ulna seems to be the same as that in the tibia and fibula. Surgery must be delayed for as long as possible in osteofibrous dysplasia of the ulna, as well as that of the tibia and fibula.