Chondrosarcoma is a malignant cartilaginous tumor, which derives its name because it makes cartilage as it grows. It occurs most often in adults between 40-60 years of age. This tumor affects the pelvis, hip, proximal femur and sometimes the shoulder and knee. Patients usually complain of a dull, persistent, aching arthritic pain with a tender mass which may slowly increase in size distorting the normal shape of the bone and extremity. Pathologic fracture is rare, but patients may experience pain caused by the large soft tissue mass putting pressure on surrounding nerves and muscles. In some patients, a preexisting enchondroma is present. A full metastatic staging workup is necessary.
Central chondrosarcomas may be low, medium or high grade. The low-grade lesions are less likely to spread. Dedifferentiated chondrosarcoma and high-grade chondrosarcoma are most likely to spread (metastasize) to other areas. Clear cell chondrosarcoma and intermediate or middle grade chondrosarcomas are less likely to spread to other areas. Juxtacortical and low-grade chondrosarcomas are least likely to metastasize. X-rays have a classic look which show a large, centrally placed lesion with significant expansion of the cortex with speckled calcifications characteristic of the the cartilaginous producing process. Sometimes the calcifications look like a 'popcorn pattern'. Examination of high-grade chondrosarcoma tissue shows clumps of jelly-like cartilage while lower grade tumors have a firmer consistency.
Treatment for chondrosarcoma is almost entirely surgical. Chemotherapy is not used unless the patient presents with lung metastases at diagnosis. Radiation is not used unless the lesion is very large or in a difficult area such as the spine or pelvis. When possible, limb-sparing procedures are used as long as wide margins can be achieved with reconstruction using metallic or allograft replacement. Low grade lesions may be treated with aggressive curettage and close observation. For high grade lesions with a large soft tissue mass, amputation may be necessary.