Chondrosarcoma.

Chondrosarcoma is the second most common primary bone tumor, with >90% of cases representing the primary conventional subtype. In addition to arising de novo, conventional chondrosarcoma can arise secondary to a benign underlying lesion, such as enchondroma or osteochondroma. Symptoms are often characterized by focal, dull, aching pain to the affected region. Grade is a well-recognized prognostic factor in these tumors. Grade I lesions/atypical cartilaginous tumors rarely metastasize, rarely recur, and have a 10-year survival rate of >80%. By contrast, grade III lesions are associated with a poor prognosis with the highest local recurrence rates, a lung metastasis rate of >50%, and a 10-year survival rate of <30%. The standard treatment of high-grade conventional chondrosarcoma is complete surgical resection with wide margin. However, low-grade lesions may be amenable to curettage plus or minus adjuvant local treatment. Conventional chondrosarcoma does not respond to chemotherapy or standard radiation doses. Adjuvant treatment can be beneficial for some subtypes such as chemotherapy for dedifferentiated and mesenchymal chondrosarcoma and radiation additionally for mesenchymal chondrosarcoma. Emerging radiation technologies may also play a useful role in treating tumors in anatomically complex areas such as the spine or pelvis.