Dedifferentiated Chondrosarcoma of Proximal Tibia and Fibula with an Infected Ulcer: A Case Report

INTRODUCTION: Dedifferentiated chondrosarcoma (DDCS) is a rare and malignant form of primary bone tumor refractive to chemotherapy and radiotherapy. It accounts for 1-2% of all primary bone tumors. Surgical resection, limb-salvage surgeries and amputation remain the mainstay of treatment. The prognosis of dedifferentiated chondrosarcoma is poor. CASE REPORT: We report a case of a 51-year-old male having a swelling and an ulcer distal to the left knee later diagnosed with dedifferentiated chondrosarcoma of proximal tibial and fibular metaphysis. Although DDCS is a highly malignant tumor, no metastasis was found and the patient was treated with transfemoral amputation. Post-operative histopathology showed nuclear atypia, binucleated and multinucleated chondrocytes with spindling and neoplastic cells arranged in storiform pattern and giant cells which confirmed the diagnosis of DDCS. CONCLUSION: Early diagnoses and treatment are important while treating these tumors in order to prevent morbidity and mortality.