Periosteal Osteosarcoma of the Distal Shaft of Fibula: Case Report on Rare Entity.

Introduction: Periosteal osteosarcoma is a rare, intermediate-grade, malignant tumor arising on the surface of the bone. There are only a few numbers of periosteal osteosarcoma of fibula reported. However, there has never been a case concerning distal fibula recorded so far. Wide surgical removal is the commonly advised treatment. In the present report, we describe a case of periosteal osteosarcoma localized to the distal fibula, which was treated by wide resection and reconstruction of ankle mortise with the ipsilateral proximal fibula.

Case Report: The patient was a 48-year-old female who presented with ankle pain and swelling. A surface lesion, with "hair on end" periosteal reaction but without obvious medullary involvement, was seen on the distal fibular shaft by imaging studies. The diagnosis of periosteal sarcoma was confirmed with tru-cut biopsy. Wide resection and ankle mortise reconstruction with ipsilateral proximal fibula were done and 1 year of follow-up shows a good outcome.

Conclusion: Periosteal osteosarcoma is a well-defined pathological entity with characteristic radiological and histological features. It is essential to distinguish it from other surface osteosarcomas as treatment modalities are different. Controversy remains about the appropriate treatment of periosteal osteosarcoma. Reconstruction of ankle mortise with reversed proximal fibular autograft is a good option in low-to-intermediate-grade periosteal osteosarcoma of the distal fibula rather than going for extensive radical procedures or adding chemotherapy to the treatment regimen.