Periosteal desmoplastic fibroma of the tibia in a 3-year-old child.

Desmoplastic fibroma is a rare benign fibrogenic, locally aggressive, primary bone tumor. It is the intraosseous counterpart of soft tissue aggressive fibromatosis. The lesion may very rarely appear as a superficial bone lesion arising from the periosteum; in such cases, a soft tissue mass with changes in the adjacent bone is evident. Periosteal lesions are very rare in the literature; diagnosis is usually based on the radiographic findings, and histological proof of the tumor origin is missing. A periosteal desmoplastic fibroma of the distal tibial metaphysis in a 3-year-old boy is presented. Radiographic investigation included plain radiographs and computed tomography imaging. Both demonstrated a soft tissue lesion involving the superficial bone tissues with non-aggressive looking borders and a pressure effect with a sclerotic rim in the bone. The lesion was excised, and the surgical as well as the histological findings indicated the diagnosis of a desmoplastic fibroma of bone arising from the periosteum. No recurrence was detected 5 years after surgery.