What is chondrosarcoma?
This information has been written for patients, their families and friends, and the general public to help them understand more about chondrosarcoma: what it is and the different types. This information is produced in accordance with BCRT's information policy.
Chondrosarcoma (KON-drow-sar-KOH-muh) is a rare cancer that most often forms in the bone, but can also very rarely appear in the soft tissue. Chondrosarcoma is the most common primary bone cancer in adulthood, and the second most common primary bone cancer overall, making up around 25% of all malignant bone cancer cases. The tumour is made of cells that produce cartilage.
Chondrosarcoma can develop in any part of the body but the most common sites are pelvis, rib cage, arms (upper arm or humerus), shoulder blades and legs (proximal femur in the thigh and the tibia in the shin). Chondrosarcomas can also be found in the spine or skull but this is extremely rare.
Also extremely rare is a type of chondrosarcoma called extraskeletal chondrosarcoma, which does not form in bone. Instead, it forms in the soft tissues of the upper part of the arms and legs. Chondrosarcomas that originate in internal organs have also been seen.
(Lor Randal and Hunt, 2010, Kim et al., 2011, Riedel et al., 2009, NCI 2010, Kleihues et al., 2006, Lewis and Ries, 2011, Rozeman et al., 2002, Chow 2007, Hogendoorn et al., 2010, Gelderblom et al., 2008).
The majority of chondrosarcomas are slow growing and do not spread, but occasionally the cancer cells can spread (metastasise) away from the bone in which they start. The likelihood that chondrosarcoma will spread will depend on the type of chondrosarcoma and the grade. If chondrosarcoma does spread from its site of origin, it usually spreads to the lungs
(Lor Randal and Hunt, 2010, Kim et al., 2011).
Classifications of chondrosarcoma
Chondrosarcoma can be described using different classifications. These classifications help doctors to decide how best to treat the tumour.
- Tumours are classed as primary or secondary.
- Primary chondrosarcomas start from cells in a healthy bone.
- Secondary chondrosarcomas arise from a benign tumour that is already present in the bone. These benign tumours include enchondroma and osteochondroma.
- The location of the tumour in the bone. Chondrosarcomas can be either:
- Central, meaning inside the bone cavity.
- Surface, meaning on the outer surface of the bone and sometimes described as periosteal. Peripheral chondrosarcomas are surface chondrosarcomas that are secondary to osteochondroma.
- When the tumour is examined under a microscope, differences can be seen between some tumour types. This classification is called the ‘histological variant’.
(Lor Randal and Hunt, 2010, Gelderblom et al., 2008, Hogendoorn et al., 2010, Lin et al., 2010, Kim et al., 2011, Atlay et al., 2007, Kliehues et al., 2006, Campanacci, 1990, Ryzewicz et al., 2007)
Chondrosarcoma should not be confused with chondroblastic osteosarcoma. This is a bone forming tumour but the tumour cells also form cartilage. The treatment for chondroblastic osteosarcoma is the same as for osteosarcoma, not chondrosarcoma.
(Lor Randal and Hunt, 2010).
(Lor Randal and Hunt, 2010, Marco et al., 2000, Kim et al., 2011, Goldberg and Grier, 2010, Gelderblom, 2008).
1) Conventional chondrosarcoma
Most chondrosarcomas (around 75% of cases) are called ‘conventional chondrosarcomas’.
(Lor Randal and Hunt, 2010, Gelderblom et al., 2008, Kim et al., 2011, Kleihues et al., 2006, Campanacci, 1990).
Conventional chondrosarcomas are further classed based on their appearance under a microscope. Pathologists examine the cells in a biopsy of the tumour and examine the size of a structure within the cells called the nucleus. The pathologist assigns the grade of the tumour to say how different the cells look from healthy cells
(Lor Randal and Hunt, 2010, Kim et al., 2011, Campanacci, 1990, Evans et al., 1977).
- Low grade tumours (grade 1)
Most cells look like normal cartilage, some cells may have two nuclei.
- Intermediate grade tumours (grade 2)
Cell nuclei are misshapen, fragmented, or bigger than in low grade tumours. Intermediate tumours are treated in the same way as high grade tumours.
- High grade tumours (grade 3)
Cells of the same type have different shapes, lots of cells are in the process of division (mitosis), giant cells and many dead cells (necrosis) can be seen.
(Lor Randal and Hunt, 2010, Ryzewicz et al., 2007, Evans et al, 1977)
Grade 1 tumours are less aggressive than grades 2 and 3 tumours, meaning that grade 1 tumours are easier to treat. Most patients have low or intermediate grade conventional chondrosarcomas although rarely, conventional chondrosarcomas can be high grade.
(Lor Randal and Hunt, 20101, Gelderblom et al., 2008, Kim et al., 2011, Evans et al., 1977, Hogendoorn et al., 2010, Campanacci, 1990).
Conventional chondrosarcomas can affect any bone. Most conventional chondrosarcomas arise from inside the bone; however, around 15% arise from cells on the surface of the bone. Conventional chondrosarcomas are equally likely to appear in the central (axial) part of skeleton as in the bones of the limbs. The thigh bone (proximal femur) is the most frequently affected followed by upper arm bone (humerus), distal femur, and ribs.
(Kim et al., 2011, Geldenblom et al., 2008, Kleihues et al, 2006).
2) Dedifferentiated chondrosarcoma
- Around 10% of chondrosarcomas are dedifferentiated chondrosarcoma.
- They are high grade and very aggressive.
- The most common sites affected are femur and pelvis.
(Lor Randal and Hunt, 2010, Kim et al., 2011, Grimer et al., 2007, Ryzewicz et al., 2007, Mitchel et al., 2000, Gelderblom et al., 2008, Milchgrub et al 2002, Nakashima et al., 1986, 2002, Kleihues et al., 2006)
3) Mesenchymal (me-ZEN-ky-mal) chondrosarcoma
- Can occur anywhere in the body – either in the bones or in non-bony (soft) tissues. If the tumour first appears in a non-bony tissue it is described as “extra-skeletal”, which means “outside of the bones”.
- Around 70% of mesenchymal chondrosarcomas originate in bone, while 30% are extra-skeletal.
- Extremely rare, accounting for less than 2% of chondrosarcomas.
- Cells of the tumour may look like cells of Ewing’s sarcoma, a different bone tumour.
- Very aggressive tumour.
(Lor Randal and Hunt, 2010, Kim et al., 2011, Goldberg and Grier, 2010, Gelderblom et al., 2008, Ryzewicz et al., 2007, Kleihues et al., 2006)
4) Clear cell chondrosarcoma
- Extremely rare, less than 2% of chondrosarcomas.
- Low grade tumours.
- The inside of the cells (cytoplasm) appears clear/ empty under the microscope.
- Tends to occur in long bones of the arms and legs.
(Kim et al., 2011, Lor Randal and Hunt, 2010, Geldenblom et al., 2008, Ryzewicz et al., 2007, Kleihues et al., 2006)
The type of treatment a patient receives will depend on which type of chondrosarcoma is diagnosed. The main treatment for chondrosarcoma is surgery to remove the tumour. Radiotherapy is sometimes used, and much more rarely chemotherapy might be used.
(Lor Randal and Hunt, 20101, Kim et al., 2011, Ryzewicz et al., 2007, Hogendoorn et al., 2010).
The authors and reviewers of this information are committed to producing reliable, accurate and up to date content reflecting the best available research evidence, and best clinical practice. We aim to provide unbiased information free from any commercial conflicts of interest. This article is for information only and should not be used for the diagnosis or treatment of medical conditions. BCRT can answer questions about primary bone cancers, including treatments and research but we are unable to offer specific advice about individual patients. If you are worried about any symptoms please consult your doctor.
Version 2 produced January 2013
Information will be reviewed in January 2015