AUTHOR AND EDITOR INFORMATION

Section 1 of 12  

• Authors and Editors
• Introduction
• Differentials
• Radiograph
• CT SCAN
• Mri
• Ultrasound
• Nuclear Medicine
• Angiography
• Intervention
• Multimedia
• References

INTRODUCTION

Section 2 of 12  

• Authors and Editors
• Introduction
• Differentials
• Radiograph
• CT SCAN
• Mri
• Ultrasound
• Nuclear Medicine
• Angiography
• Intervention
• Multimedia
• References

Background

Chondrosarcoma is the second most frequent primary malignant tumor of bone, representing approximately 25% of all primary osseous neoplasms. Chondrosarcomas are a group of tumors with highly diverse features and behavior patterns, ranging from slow-growing non-metastasizing lesions to highly aggressive metastasizing sarcomas.

Pathophysiology

Chondrosarcoma is a malignant tumor of cartilaginous origin, in which the tumor matrix formation is entirely chondroid in nature.

Chondrosarcomas are classified as central (originating within the intramedullary canal) or peripheral. Rarely, they may arise as juxtacortical lesions. Lesions are designated as primary when they arise de novo or as secondary when they occur within a preexisting lesion such as an enchondroma or osteochondroma.

Tumors are further categorized by grade. Grade 1 represents the least aggressive in terms of histologic features, and grade 3 represents the most aggressive. Most chondrosarcomas are pathologically classified as conventional, but other subgroups are clear cell, myxoid, mesenchymal, and dedifferentiated. This article deals exclusively with conventional chondrosarcomas of the bone.

Frequency

United States

The incidence rate of chondrosarcoma is dependent on patient age, peaking at 8 cases per 1 million population in those aged 80-84 years. The incidence in children is low. Most tumors arise in patients older than 40 years. The risk of chondrosarcoma is increased in people with enchondromatosis syndromes (eg, Ollier disease, Maffucci syndrome, metachondromatosis) and in those with hereditary multiple exostosis (eg, diaphyseal aclasis). Patients with these conditions are generally younger than other patients at presentation.

Mortality/Morbidity

The overall prognosis is related to the size of the lesion, its anatomic location, and its histologic grade.

• Axial lesions have a worse prognosis than those in the appendicular skeleton.
• The 5-year survival rate for grade 1 lesions is 90%, and the rate decreases to 29% for grade 3 tumors. Grade 1 lesions do not metastasize. Metastatic spread, typically pulmonary, is more frequently associated with grade 3 lesions than with others. Lymph node spread is more common than with other osseous neoplasms.
• Tumor recurrence typically occurs 5-10 years after surgery, and it is often associated with more aggressive behavior and a histologic grade higher than that of the original lesion.

Race

No major difference in incidence is observed between ethnic groups.

Sex

A slight male predilection exists, with a male-to-female ratio of 1.5-2:1.

Age

The age range is wide, but most cases occur in patients older than 40 years.

• Secondary chondrosarcomas tend to occur in younger patients, namely, those aged 20-40 years.
• Chondrosarcoma is rare in children, but it tends to be aggressive.

Anatomy

Tumors are predominantly axial, and they most commonly involve the pelvic bones, femur, humerus, ribs, scapula, sternum, or spine. In tubular bones, the metaphysis is the most common site of origin. The proximal metaphysis is more frequently involved than the distal end of the bone. Involvement of the distal humerus is most unusual. Chondrosarcoma is rare in the hands and feet and usually occurs as a complication of a multiple enchondromatosis syndrome. Chondrosarcoma arising de novo in the hands and feet is also extremely unusual.

Clinical Details

The most common symptom at presentation is pain, which is often present for months and typically dull in character. It may be worse at night. Local swelling may be present, and when the tumor occurs close to a joint, effusion may be present, or movement may be restricted. The average duration of symptoms prior to presentation is 1-2 years. The tumor may occasionally occur as a pathologic fracture.

Preferred Examination

Radiographs are essential for the initial diagnosis, and it is sometimes supplemented with CT, which is more sensitive for detecting matrix calcification and for confirming deep endosteal cortical scalloping in intramedullary tumors.

MRI is the preferred modality for evaluating the extent of intramedullary tumors and demonstrating extraosseous extension. MRI is useful in evaluating the thickened cartilage cap in an osteochondroma that develops a secondary chondrosarcoma. MRI is less sensitive than CT in identifying small amounts of matrix calcification within a tumor.

The imaging appearances of chondrosarcoma can overlap with those of other lesions, especially other cartilaginous tumors such as enchondroma. The presence of pain with any lesion (without a pathologic fracture in lesions of the hands and feet) is highly suggestive of malignancy. Other findings suggestive of malignancy in a cartilaginous tumor include endosteal cortical scalloping of more than two thirds of the thickness of the cortex, ill-defined border and/or zone of transition, and a large soft tissue mass. Both benign and malignant cartilaginous tumors may show a central lucency. However, lucency of an area that previously showed matrix calcification is a highly suggestive feature.

Limitations of Techniques

See Preferred Examination above.

DIFFERENTIALS

Section 3 of 12  

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• Introduction
• Differentials
• Radiograph
• CT SCAN
• Mri
• Ultrasound
• Nuclear Medicine
• Angiography
• Intervention
• Multimedia
• References

Other Problems to be Considered

Central
Enchondroma
Osteosarcoma
Fibrosarcoma
Bone infarct

Peripheral
Osteochondroma
Parosteal osteosarcoma

RADIOGRAPH

Section 4 of 12  

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• Radiograph
• CT SCAN
• Mri
• Ultrasound
• Nuclear Medicine
• Angiography
• Intervention
• Multimedia
• References

Findings

Radiographs typically show a lucent lesion, which frequently contains matrix calcification, particularly in well-differentiated tumors. The degree of organization of the matrix calcification can be correlated with the grade of the tumor. Aggressive tumors contain irregular calcifications, and they often have large areas showing no calcification at all. Well-differentiated lesions tend to have more developed matrix with the typical appearance of rings and arcs.

The margin of intramedullary lesions is determined by the degree of aggression of the tumor, and it is frequently ill defined. Endosteal scalloping may be present, and when its depth is more than two-thirds the normal thickness of the cortex, this scalloping is useful in distinguishing chondrosarcoma from enchondroma, except in lesions of the hands and feet. Benign enchondromas in these areas can cause considerable cortical thinning, and they may occur as a pathologic fracture.

Cortical destruction and/or a soft tissue mass are indicators of the malignant nature of the tumor. Destruction of matrix calcification that was previously visible in an enchondroma is also an indicator of malignant transformation.

Degree of Confidence

The size of the tumor is often poorly assessed on radiographs alone, and MRI is advised to demonstrate both the intramedullary and the soft tissue extent of the lesion. CT can be helpful in identifying matrix calcification in some lesions that appear entirely lucent on radiographs.

CT SCAN

Section 5 of 12  

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• Radiograph
• CT SCAN
• Mri
• Ultrasound
• Nuclear Medicine
• Angiography
• Intervention
• Multimedia
• References

Findings

In as many as 90% of cases, tumors appear as lucent areas containing chondroid matrix calcification. Endosteal scalloping and cortical destruction are frequently easier to appreciate on CT scans than on radiographs.

CT can be used to guide percutaneous biopsy, and it is the modality of choice for investigating possible pulmonary metastatic disease.

Degree of Confidence

CT can often be used to successfully categorize the lesion as being of cartilaginous origin. Its medullary extent can be assessed more accurately with CT than with radiography. However, MRI is superior, and it is also the most useful modality for determining soft tissue extension.

MRI

Section 6 of 12  

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• Mri
• Ultrasound
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• Multimedia
• References

Findings

MRI typically demonstrates lobulated lesions of high signal intensity on T2-weighted images. Lobules are commonly separated by low-signal-intensity septa. On T1-weighted images, the lesion generally has low signal intensity.

Areas of matrix calcification are shown as signal voids on images obtained with all sequences, but small amounts may not be identifiable. MRI may demonstrate large aggregates of calcium, but tiny scattered calcifications may be completely missed because of partial-volume averaging. MRI can be used to assess soft tissue extension and the intramedullary extent of the tumor. MRIs can demonstrate endosteal cortical scalloping, but this feature is more easily assessed by using CT.

MRI is useful in assessing the thickness of the cartilage cap of osteochondromas to identify chondrosarcoma transformation. Chondrosarcomas show variable patterns of enhancement after the administration of contrast material.

Degree of Confidence

MRI is the method of choice for clarifying the intramedullary and extraosseous extent of a chondrosarcoma, but features related to cortical bone and matrix calcification are more accurately assessed by using CT.

ULTRASOUND

Section 7 of 12  

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• Ultrasound
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• Multimedia
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Findings

Ultrasonography has no role in evaluating intramedullary lesions confined to the bone. It can demonstrate soft tissue extension; therefore, it may be useful in guiding percutaneous biopsy.

Ultrasonography is useful as a means of assessing the thickness of the cartilage cap overlying an osteochondroma, although access to the lesion can be difficult in certain areas. If the cap measures more than 1.5 cm in a skeletally mature patient, transformation to chondrosarcoma may have occurred.

NUCLEAR MEDICINE

Section 8 of 12  

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Findings

Central chondrosarcomas typically show significantly increased uptake of the radioisotope on isotopic bone scans, but differentiation between chondrosarcoma and enchondroma is unreliable. Uptake on isotopic bone scanning indicates metabolic activity in an osteochondroma, but it cannot be used to distinguish this type of uptake from uptake due to malignant transformation. The absence of increased uptake makes malignancy highly unlikely.

Degree of Confidence

See Findings above.

ANGIOGRAPHY

Section 9 of 12  

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• Multimedia
• References

Findings

Angiography is generally not required in the staging of chondrosarcoma.

INTERVENTION

Section 10 of 12  

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Histologic confirmation of the nature of a lesion is required for optimal management. Although biopsy is often performed as an open surgical procedure, percutaneous biopsy with imaging guidance can be helpful in certain scenarios. Ultrasonography is useful for guiding needle biopsy of the soft tissue component of a tumor. CT-guided percutaneous biopsy of bone lesions may be helpful, but the pathologic differentiation between benign and low-grade malignant chondrosarcomas is difficult. Needle biopsy samples may be inadequate to allow precise pathologic diagnosis, and open surgical biopsy is often performed.

The mainstay of treatment is surgical resection because chondrosarcomas respond poorly to chemotherapy or radiation therapy.

Medical/Legal Pitfalls

• Although they are malignant tumors, chondrosarcomas often show features suggestive of a benign lesion.
• Readers should be cautious not to mistake them for benign lesions because of their well-circumscribed appearance and lack of periosteal reaction.

MULTIMEDIA

Section 11 of 12  

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• Radiograph
• CT SCAN
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• Ultrasound
• Nuclear Medicine
• Angiography
• Intervention
• Multimedia
• References

Media file 1:  Frontal radiograph of the left fibula head demonstrates a lucent lesion that contains the typical chondroid matrix calcification. Low-grade tumor.
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Media type:  X-RAY

Media file 2:  Frontal radiograph of the left acetabulum demonstrates an expansile lucent lesion with no internal matrix calcification (same patient as in Images 2-5). Low-grade central tumor.
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Media type:  X-RAY

Media file 3:  Bone-window CT scan of left acetabulum demonstrates matrix calcification in the expansile lucent lesion in the anterior column (same patient as in Images 2-5). Low-grade central tumor.
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Media type:  CT

Media file 4:  T2-weighted axial MRI of the pelvis demonstrates the high signal intensity of the acetabular lesion (same patient as in Images 2-5). Low-grade central tumor.
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Media type:  MRI

Media file 5:  T1-weighted axial MRI of the pelvis demonstrates the low signal intensity of the acetabular lesion (same patient as in Images 2-5). Low-grade central tumor.
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Media type:  MRI

Media file 6:  Frontal radiograph of right side of upper abdomen demonstrates a destructive, expansile lesion of the 12th rib. The lesion contains irregular calcification (same patient as in Image 7). High-grade central tumor.
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Media type:  X-RAY

Media file 7:  CT of the right side of the upper abdomen demonstrates the expansile tumor with a large associated soft tissue mass containing foci of calcification (same patient as in Image 6). High-grade central tumor.
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Media type:  CT

Media file 8:  Frontal radiograph of the pelvis demonstrates extensive calcification overlying the left ilium and in the lateral soft tissues. No bone destruction is shown (same patient as in Images 9-10). High-grade secondary peripheral tumor.
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Media type:  X-RAY

Media file 9:  CT scan of the pelvis demonstrates a large soft tissue mass that contains calcification arising from a broad-based sessile osteochondroma on the posterior aspect of the ilium (same patient as in Images 8 and 10). High-grade secondary peripheral tumor.
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Media type:  CT

Media file 10:  T2-weighted axial MRI of the pelvis demonstrates a lobulated high-signal-intensity soft tissue with local-signal-intensity septa arising from the osteochondroma on the posterior aspect of the ilium (same patient as in Images 9-10). Several areas of low signal intensity are shown; these correspond to focal areas of dense calcification. This appearance is typical of cartilaginous material. High-grade secondary peripheral tumor.
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Media type:  MRI

Media file 11:  Lateral radiograph of the distal femur in a patient with hereditary multiple exostoses (same patient as in Images 12-13). Several osteochondromas of varying appearances arise from the metaphyseal region; these typically grow away from the joint. Soft tissue calcification is shown overlying the most posterior osteochondroma. High-grade secondary peripheral tumor.
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Media type:  X-RAY

Media file 12:  CT scan of the distal femur demonstrates a broad-based osteochondroma with a thick overlying soft tissue cap that contains focal calcification. The metaphyseal contour is irregular because of the presence of several other osteochondromas in this patient with hereditary multiple exostoses (same patient as in Images 11 and 13). High-grade secondary peripheral tumor.
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Media type:  CT

Media file 13:  Fast spin-echo T2-weighted axial MRI of the distal femur in a patient with hereditary multiple exostoses (same patient as in Images 11-12). Image demonstrates the thick cartilage cap overlying a broad-based osteochondroma. Areas of focal reduced signal intensity in the cartilage cap correspond to foci of dense calcification. High-grade secondary peripheral tumor.
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Media type:  MRI

REFERENCES

Section 12 of 12

• Authors and Editors
• Introduction
• Differentials
• Radiograph
• CT SCAN
• Mri
• Ultrasound
• Nuclear Medicine
• Angiography
• Intervention
• Multimedia
• References

• Bauer HC, Brosjo O, Kreicbergs A, Lindholm J. Low risk of recurrence of enchondroma and low-grade chondrosarcoma in extremities. 80 patients followed for 2-25 years. Acta Orthop Scand. Jun 1995;66(3):283-8. [Medline].
• Flemming DJ, Murphey MD. Enchondroma and chondrosarcoma. Semin Musculoskelet Radiol. 2000;4(1):59-71. [Medline].
• Healey JH, Lane JM. Chondrosarcoma. Clin Orthop. Mar 1986;(204):119-29. [Medline].
• Hudson TM, Chew FS, Manaster BJ. Radionuclide bone scanning of medullary chondrosarcoma. AJR Am J Roentgenol. Dec 1982;139(6):1071-6. [Medline].
• Marco RA, Gitelis S, Brebach GT, Healey JH. Cartilage tumors: evaluation and treatment. J Am Acad Orthop Surg. Sep-Oct 2000;8(5):292-304. [Medline].
• Murphey MD, Flemming DJ, Boyea SR, et al. Enchondroma versus chondrosarcoma in the appendicular skeleton: differentiating features. Radiographics. Sep-Oct 1998;18(5):1213-37; quiz 1244-5. [Medline].
• Resnik D, Kyriakos M, Greenaway GD. Tumors and tumor-like lesions of bone: imaging and pathology of specific lesions. In: Diagnosis of Bone and Joint Disorders. 4th ed. Philadelphia, Pa: WB Saunders Co;2002: 3897-919.
• Wang XL, De Beuckeleer LH, De Schepper AM, Van Marck E. Low-grade chondrosarcoma vs enchondroma: challenges in diagnosis and management. Eur Radiol. 2001;11(6):1054-7. [Medline].

Article Last Updated: Aug 11, 2005