Giant Cell Tumor of the Lateral Malleolus Treated by Tumor Excision and Reconstruction using A 180° Rotated Proximal Fibular Autograft - A Rare Case Report.

INTRODUCTION: Giant cell tumor (GCT) of bone was first described by Sir Astley Cooper in 1818. It is one of the most frequently encountered benign bone tumors in orthopedic practice and is characterized by a significant risk of local recurrence following surgical treatment. GCT involving the distal fibula, particularly the lateral malleolus, is extremely rare, accounting for <1% of all cases. Various treatment modalities have been described for lateral malleolus GCT, including tumor excision, ankle arthrodesis, reconstruction with ipsilateral proximal fibular graft, and autograft or allograft reconstruction. This report presents the management of a Campanacci Grade II GCT of the lateral malleolus involving the epiphysis and metaphysis, with compression of the lateral collateral ligament complex, peroneal muscles and tendons, and the talus. The patient was successfully treated with tumor excision, reconstruction using an ipsilateral proximal fibular graft, and ankle joint reconstruction. This technique preserved ankle stability while maintaining joint mobility.

CASE REPORT: A 26-year-old male presented with a 6-month history of swelling and pain over the lateral aspect of the ankle. Radiological evaluation and histopathological examination were performed to establish the diagnosis and plan treatment. The patient underwent complete surgical excision of the tumor followed by reconstruction using an ipsilateral proximal fibular graft. Histopathological analysis confirmed the diagnosis of a Grade I GCT without evidence of malignant transformation.

CONCLUSION: Due to the rarity of distal fibular GCT, the optimal surgical approach and its impact on ankle stability remain subjects of debate. The reconstruction technique described in this case provides a viable option for managing such uncommon lesions, offering effective tumor control, preservation of ankle stability, and maintenance of functional joint movement. This method may serve as a valuable reference for future reconstruction procedures in similar rare clinical scenarios.