Abstract
BACKGROUND: Dedifferentiated chondrosarcoma represents a special form of the chondrosarcoma characterized by the presence of well-differentiated cartilaginous component in juxtaposition with the malignant mesenchymal tumor of high-malignancy grade. METHODS: The study was performed on 25 tissue samples obtained by biopsy of the primary malignant bone tumors. RESULTS: Out of the total of 25 patients, 13 were males and 12 were females. Their average age was 59.9 years (39-75). Radiological examination verified the presence of the pathological fractures in 14 patients. The skeletal distribution clearly indicates that the femur is the most frequent site of affection (in 15 patients--60%). Morphological analysis verified the presence of "precursor cartilaginous lesion" or low-grade cartilaginous component in all cases. Classification of the high-grade components was based on the immunohistochemical analyses, which evidenced MFH in 18 cases, osteosarcoma in 4, while fibrosarcoma was evidenced in 2 and rhabdomyosarcoma in 1 case. In 20 patients, out of whom 14 had existing fractures, amputation was indicated. In five patients (fracture-free), resection limb-salvage surgical intervention was performed. CONCLUSION: The lethal outcome ensues within less than 2 years in all patients.