The giant aggressive chondroma: A rare entity, a difficult approach

Introduction: enchondromas rarely exceed 3–6 cm in long bones. Although the risk of developing secondary chondrosarcoma has been reported up to 4% in solitary lesions, it is not known if size represents a risk factor for transformation. Objective: to describe three exceptional cases of enchondromas of the entire femur whereof one dedifferentiated in chondrosarcoma. Results: two patients present stable disease at 5 and 6 years of follow-up; the third, already diagnosed with a dedifferentiated chondrosarcoma, died 14 months after the index surgery for systemic disease. Conclusion: based on these observations, our hypothesis is that lesion size is an important risk factor for malignant transformation.