Abstract
INTRODUCTION: Extra-axial chordomas are extremely rare tumours that are characterised by slow growth and local aggressiveness and can potentially metastasise during follow-up. MATERIALS AND METHODS: This is the case of a 37-year-old woman with a bone lesion in the distal third of her fibula, with mild symptoms at that site consisting of a mass and mild pain. After local and distant staging, a percutaneous core needle biopsy was performed and a diagnosis of malignant bone tumour with cartilage differentiation was made, although the diagnosis and lesion grade could not be specified. RESULTS: After evaluation by the sarcoma committee, and given the biopsy diagnosis and negative distant extension, wide resection and reconstruction of the tibio-fibular reconstruction complex were performed. The definitive diagnosis was a well-differentiated extra-axial chondroid bone chordoma in the cortex of the fibula. Four years after the procedure, the patient is disease free, with good ankle function and independent in her activities of daily living. An AOFAS score of 62 points, an MSTS-ISOLS score of 18 points (60%) and SF-12 scores of 35.56 on the PCS and 24.58 on the MCS were recorded. CONCLUSION: Bone and soft tissue neoplasms require local and distant staging prior to biopsy. For a suspected diagnosis, clinical, anatomical and radiological correlation must be maintained. Treatment can proceed after the case has been reviewed by a multidisciplinary sarcoma committee. In chordoma cases, extra-axial locations are extremely rare. Reconstruction of the ankle presents major anatomical difficulties, with multiple techniques having been described. In such cases, a careful pre-surgical anatomical study must be performed to obtain wide margins and plan the reconstruction based on the type of patient, anatomical structures after resection and the multiple techniques described for the lateral ankle region, in order to maintain maximum function without limiting the patient's quality of life.