Dedifferentiation of low grade chondrosarcomas.

In four unusual cases where a low-grade chondrosarcoma suddenly dedifferentiated into a florid, highly-malignant fibrosarcoma, the average survival was 12 months (range 5-18 months). The surgical treatment of chondrosarcoma consists of a primary excisional biopsy, and if dedifferentiation to fibrosarcoma is seen, radical excision and chemotherapy or irradiation or both.