Congenital (infantile) pseudarthrosis of the fibula associated with osteofibrous dysplasia.

We describe a recently noted association of congenital (infantile) pseudarthrosis of the lower leg with osteofibrous dysplasia. The patient was a 2-year-old boy who presented with a deformed left ankle joint and three cutaneous cafe-au-lait spots. Radiography demonstrated pseudarthrosis of the left distal fibula and a round lucent lesion adjacent to the proximal part of the pseudarthrosis. Histologically, the surgically removed fibula with pseudarthrosis showed a fibromatosis-like fibrovascular proliferation and nonspecific reparative changes. The focal lucent area demonstrated a fibro-osseous lesion, which was histologically identical to osteofibrous dysplasia. This case provides further evidence that osteofibrous dysplasia may be associated with congenital (infantile) pseudarthrosis of the lower leg.