The Clinical Approach Towards Chondrosarcoma

Abstract

Learning Objectives: After completing this course, the reader will be able to: Classify the chondrosarcoma subtypes.Engage in the diagnostic process of chondrosarcoma.Evaluate the treatment options for chondrosarcoma. CME Access and take the CME test online and receive 1 AMA PRA Category 1 Credit™ at CME.TheOncologist.com This review provides an overview of the histopathology, classification, diagnostic procedures, and therapy of skeletal chondrosarcoma. Chondrosarcomas that arise de novo are primary chondrosarcomas, whereas chondrosarcomas developing superimposed on pre-existing benign cartilage neoplasms such as enchondromas or osteochondromas are referred to as secondary chondrosarcomas. Conventional chondrosarcomas can be categorized according to their location in bone into central, peripheral, and juxtacortical chondrosarcomas. Histological grading is related to prognosis; however, it is also subject to interobserver variability. Rare subtypes of chondrosarcoma, including dedifferentiated, mesenchymal, and clear cell chondrosarcoma, are discussed as well. Magnetic resonance imaging is necessary to delineate the extent of the intraosseous and soft tissue involvement preoperatively. Computed tomography is especially recommended in the pelvis and other flat bones where it may be difficult to discern the pattern of bone destruction and the presence of matrix mineralization. Wide, en-bloc excision is the preferred surgical treatment in intermediate- and high-grade chondrosarcoma. In low-grade chondrosarcoma confined to the bone, extensive intralesional curettage followed by local adjuvant treatment and filling the cavity with bone graft has promising long-term clinical results and satisfactory local control. Chondrosarcomas are relatively radiotherapy resistant; therefore, doses >60 Gy are needed in attempts to achieve local control after incomplete resection. Irradiation with protons or other charged particles seems beneficial in this curative situation. Chemotherapy is only possibly effective in mesenchymal chondrosarcoma, and is of uncertain value in dedifferentiated chondrosarcoma. Potential new systemic treatment targets are being discussed.