Skip to main content

Diagnosis & Discussion


Chondrosarcoma, mixed classical and clear cell types. Grade 2 for classical component.


Chondrosarcoma is the collective term for a group of heterogeneous, generally slow-growing, primary malignant tumors of bone characterized by the formation of hyaline cartilaginous neoplastic tissue. These tumors predominantly occur in adults and are the second most common primary solid tumor of bone after osteogenic sarcoma.

Chondrosarcomas that arise unassociated with a pre-existing lesion are called primary chondrosarcoma, versus secondary if they arise from a pre-existing benign cartilage tumor (i.e. enchondroma or osteochondroma). Malignant transformation occurs in 5% of osteochondromas, either in multiple or solitary forms.

Conventional chondrosarcoma accounts for 85-90% of chondrosarcomas. Non-conventional chondrosarcoma variants include clear cell chondrosarcoma, mesenchymal chondrosarcoma, and dedifferentiated chondrosarcoma. Dedifferentiated chondrosarcoma develop when low-grade conventional chondrosarcoma transform into a high-grade sarcoma, most frequently exhibiting features of osteosarcoma, fibrosarcoma, or undifferentiated pleomorphic sarcoma (UPS).

Chondrosarcomas are large tumors, usually greater than 4 cm in size4. Histologically they show abundant blue-grey cartilagenous matrix. Irregularly shaped lobules of cartilage of varying size are present. Fibrous bands separate these lobules or permeate bony trabeculae. Calcified areas suggesting the presence of a pre-existing enchondroma can often be found. The chondrocytes are atypical, with variable size and shape and contain enlarged hyperchromatic nuclei. Binucleation is frequently seen. Chondroid matrix liquefaction or myxoid changes are a common feature of chondrosarcomas. Necrosis and mitoses can be seen. There is often permeation into the cortical bone and the marrow space with entrapment of bony trabeculae. Chondrosarcomas are graded on a scale from 1 to 3, based upon nuclear size, staining pattern (hyperchromasia), mitotic activity, and degree of cellularity.

Chromosomal anomalies detected in some types of chondrosarcomas include at 9p21, 10, 13q14, and 17p13. Moreover, the amplification of MYC and AP-1 transcription factors plays a vital role in the pathogenesis of this type of tumor.

The prognosis for the majority of patients with chondrosarcoma is favorable and correlates with histologic grade and adequate surgical margins. Development of metastatic disease is typically an ominous sign and is related to characteristic chemotherapy and radiation resistance of this tumor. This feature is a result of its underlying phenotype: poor vascularization, slow division rate, and hyaline cartilaginous matrix prohibiting the access of therapeutic agents to the cells.


Chow WA. Chondrosarcoma: biology, genetics, and epigenetics. F1000Res 2018;7 doi: 10.12688/f1000research.15953.1

Nazeri E, Gouran Savadkoohi M, Majidzadeh AK, et al. Chondrosarcoma: An overview of clinical behavior, molecular mechanisms mediated drug resistance and potential therapeutic targets. Crit Rev Oncol Hematol 2018;131:102-09. doi: 10.1016/j.critrevonc.2018.09.001

Limaiem F, Davis DD, Sticco KL. Chondrosarcoma. StatPearls. Treasure Island (FL)2021.

Murphey MD, Walker EA, Wilson AJ, et al. From the archives of the AFIP: imaging of primary chondrosarcoma: radiologic-pathologic correlation. Radiographics 2003;23(5):1245-78. doi: 10.1148/rg.235035134

Heck RK, Jr., Peabody TD, Simon MA. Staging of primary malignancies of bone. CA Cancer J Clin 2006;56(6):366-75. doi: 10.3322/canjclin.56.6.366


Go Back