Dedifferentiated chondrosarcoma--a fatal disease

We report on 13 patients with dedifferentiated chondrosarcomas. The mean age of the patients at diagnosis was 59.8 years. Nine patients were classified as stage IIB and four as stage III.

In 11/13 cases surgery was performed. Mostly, limb salvage with tumour resection and implantation of a megaprosthesis was done; three patients needed amputation or disarticulation. In one out of three patients with a pelvic tumour resection was followed by implantation of a pelvic replacement; the other two patients received tumour resection with autologous stabilisation of the pelvis. Surgical margins were wide in six patients, marginal in two and intralesional in three. Adjuvant chemotherapy was given to five patients.

Recurrence was detected in 5/11 of the patients operated on: in two with wide, in one with marginal, and in two with intralesional resection. No recurrence was seen in 5/11 patients: in four after wide and in one after marginal resection. In one patient the stage was unknown. At follow-up 11 patients were dead of disease (DOD), one dead of unknown reason (DOU) and one alive with disease (AWD). The mean survival time was 9.7 months. Metastasis to different anatomical sites was evident after a period of 10 months.

Our results resemble those reported in the literature. DDCS is rare and is the primary malignant bone tumour with the worst prognosis. Surgery is the most important procedure, although it is unclear whether a radical resection improves the long-term results. Information regarding neoadjuvant and/or adjuvant therapy with chemotherapy is very limited.