Clear Cell Chondrosarcoma

Summary
Description

Clear Cell Chondrosarcoma is a destructive low-grade malignant tumor which presents in adults. Clear cell chondrosarcoma is uncommon and accounts for about 2% of all chondrosarcomas.

People and Age
Most patients diagnosed with clear cell chondrosarcoma were in 3rd and 4th decades of life. Most common location is in epiphysis. The most common sites of involvement are the proximal femur, proximal humerus, distal femur and proximal tibia.
Symptoms and Presentation
The most common symptoms are pain and swelling, that usually are of long duration. There may be limitation of the range of motion of the involved joint.


Brief description of the xray
On radiographs, these tumors are well-circumscribed mixed lucent and sclerotic lesions with an active appearance.
Brief desc of tx
Treatment and prognosis: En bloc resection with a wide margin of normal bone and soft tissue is the procedure of choice.
Tumor Type
Benign or Malignant
Most Common Bones
Location in bone
Periosteal reaction
Position within the bone
Tumor behavior
Tumor density
Complete Information on this Tumor
Introduction and Definition

Clear Cell Chondrosarcoma is a destructive low-grade malignant tumor which presents in adults. Clear cell chondrosarcoma is uncommon and accounts for about 2% of all chondrosarcomas.

Incidence and Demographics
This tumor appears to occur more often in men than in women. Adults in their 30,s, 40's and 50's are mot commonly affected, but older and younger patients have been reported.
Symptoms and Presentation

The tumor is a slow growing lesion that has a predeliction for the epiphysis of major long bones. Therefore, gradual onset of joint-related pain in the hip or shoulder is a typical presentation. Sometimes a pathological fracture will force the patient to see treatment for the lesion, even though there has been minor to moderate aching pain for years. The overall presentation of this lesion mimics that of a benign bone tumor.

X-Ray Appearance and Advanced Imaging Findings
On radiographs, these tumors are well-circumscribed mixed lucent and sclerotic lesions with an active appearance. With time they will expand the bone. The margins in some areas are well defined and may have a sclerotic rim, but in other areas the margins of the tumor are moderately well defined or "flowing." The matrix mineralization does not have the regular appearance of ground glass, yet neither does it have a typical "popcorn" or "ring and arc" chondroid pattern. In the absence of fracture, no periosteal reaction is present. The cortex may be expanded and thinned but is not breached or destroyed in an aggressive manner. Since the epiphysis is a common location, the tumors are most likely to be diagnosed radiologically as chondroblastoma, and it may be impossible to distinguish the two based on radiographs. However, the lesions may occur in the metaphysis or diaphysis or extend into those locations with growth. In some lesions the slow pace of growth is well demonstrated by evidence of gradual non-destructive enlargement of bone. CT scan is very helpful to demonstrate the extent of the lesion, the details of the matrix calcification,and the appearance of the margins.
Laboratory Findings
Serum alkaline phosphatase may be a useful marked for this tumor.
Differential Diagnosis
Differential diagnosis: chondroblastoma is a major consideration, because many clear cell chondrosarcomas occur in the epiphyseal ends of long bones.
Metastatic clear cell carcinomas, such as from the kidney, may cytologically resemble clear cell chondrosarcoma, although the glandular architecture or lumen formation of the formers is not seen in clear cell chondrosarcoma.
Preferred Biopsy Technique for this Tumor
Incisional, staged. Biopsy and surgery should not occur in one stage.
Histopathology findings
Gross findings: on cut surface, clear cell chondrosarcoma lacks the appearance of conventional chondrosarcoma and is, instead, usually red, soft, and granular.

Histlogically clear cell chondrosarcoma contains many chondrocytes with abundant clear, vacuolated cytoplasm, which may lie between heavily calcified trabeculae of cartilage matrix that may resemble bone. The abundant mostly accellular cartilage matrix seen in enchondroma is completely absent. In other areas of the tumor the vacuolated cells are packed together like pomegranate seeds or cobblestones, in a manner somewhat reminiscent of chondroblastoma. Multinucleated osteoclast-like cells with a few nuclei are frequently present, either as individual cells or small clusters. The giant cell component is not a prominent feature. The nuclei in the giant cells do not resemble the stromal cells.
Treatment Options for this Tumor
Clear cell chondrosarcomas are locally aggressive, and metastases have been reported. En bloc resection with a wide margin of normal bone and soft tissue is the procedure of choice.
Outcomes of Treatment and Prognosis
In any rare tumor, the small numbers of patients with adequate follow up make it difficult to calcualte precise prognosis figures. On one series from the Mayo clinic, 10 year overall survival was 89% and 10 year disease free survival was 68%. The rate of distant metastasis was 25% in that series. If this tumor is treated with simple curettage, local recurrence can be expected in most cases, and is reported in 70%. Local recurrence is found on average 50 - 60 months after treatment. Local recurrence may occur from 12 to 120 months or more after initial treatment. Distant bone metastasis occurs in a significant number of patients who have local recurrence, so it can be inferred that inadequate initial treatment is a risk factor for a poor outcome in these tumors. However, this has not been proven.
Special and Unusual Features
In one series by Donati e al, 44% of patients with clear cell chondrosarcoma initially received inappropriate treatment, usually simple curettage or attempted fracture repair without adequate treatment of this malignant tumor. The overall presentation of this lesion mimics that of a benign bone tumor and should serve as a reminder to all clinicians treating bone tumors of the pitfalls that lie in the path to the correct treatment of these lesions.
Suggested Reading and Reference
Arch Orthop Trauma Surg. 2008 Feb;128(2):137-42. Epub 2007 May 24.
Clear cell chondrosarcoma of bone: long time follow-up of 18 cases.Donati D, Yin JQ, Colangeli M, Colangeli S, Bella CD, Bacchini P, Bertoni F. Clin Orthop Relat Res. 2005 Nov;440:209-12.
An institutional review of clear cell chondrosarcoma.Itälä A, Leerapun T, Inwards C, Collins M, Scully SP.
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