|Year : 2016 | Volume
| Issue : 2 | Page : 261-263
Dedifferentiated chondrosarcoma of right proximal femur
Sachin A Badge1, Nitin M Gangane2, Vitaladevnni B Shivkumar2, Satish M Sharma2
1 Department of Pathology, Late Baliram Kashyap Memorial Government Medical College, Jagdalpur, Chhattisgarh, India
2 Department of Pathology, Mahatma Gandhi Institute of Medical Sciences, Sevagram, Maharashtra, India
|Date of Web Publication||1-Mar-2016|
Sachin A Badge
Department of Pathology, Late Baliram Kashyap Memorial Government Medical College, Jagdalpur, Chhattisgarh
Source of Support: None, Conflict of Interest: None
Dedifferentiated chondrosarcoma (DDCS) comprises approximately 10% of all chondrosarcomas. The tumor generally occurs after the age of 50 years, with equal distribution among males and females. It is most often located in the bones of the pelvis, the proximal femur or humerus, the distal femur, and the ribs. Regardless of treatment, the prognosis is ominous with 90% of patients dying with distant metastases within 2 years. We report a case of DDCS of right proximal femur in a 73-year-old woman. The most important factors affecting survival are early recognition of the radiographic features, adequate histological sampling, and wide-margin resection of the lesion. So for the correct histopathological diagnosis the biopsy sample should be adequate to visualize both cartilaginous and noncartilaginous sarcomatous component which helps to increase the survival of patients before the distant metastasis occurs.
Keywords: Chondrosarcoma, dedifferentiated, sarcoma
|How to cite this article:|
Badge SA, Gangane NM, Shivkumar VB, Sharma SM. Dedifferentiated chondrosarcoma of right proximal femur. Med J DY Patil Univ 2016;9:261-3
| Introduction|| |
The term dedifferentiated chondrosarcoma (DDCS) is applied to a high-grade sarcoma occurring next to a low-grade malignant cartilage-forming tumor; it comprises approximately 10% of all chondrosarcomas. The tumor generally occurs after the age of 50 years, with males and females equally affected. It is most often located in the bones of the pelvis, the proximal femur or humerus, the distal femur, and the ribs. Regardless of treatment, the prognosis is ominous with 90% of patients dying with distant metastases within 2 years. 
| Case Report|| |
A 73-year-old female patient presented with complaints of pain and swelling in right hip since 15 days. X-ray and magnetic resonance imaging (MRI) of right hip joint showed an osteolytic lesion with subtrochanteric fracture of right proximal femur [Figure 1] and [Figure 2]. Fine needle aspiration cytology showed only chondroid material with atypical chondrocytes, so diagnosis of low-grade chondrosarcoma was given, and we advised histopathological examination for confirmation [Figure 3]. We received biopsy from right proximal femur which was composed of very tiny pieces of gray-white tissue together aggregating 1 cm × 0.5 cm × 0.5 cm. The microscopic examination showed only fibrous element having nuclear atypia at places and areas of ossification. No chondroid element was seen. Hence, impression of malignant mesenchymal tumor was given, and we advised to send larger specimen for histopathological examination. After that, we received excisional biopsy specimen from right proximal femur which was composed of multiple gray, white tissue fragments along with tiny bony pieces together aggregating 2 cm × 1.5 cm × 0.5 cm. The microscopic examination showed lobules of cartilage having pleomorphic, hyperchromatic nuclei of chondrocytes (low-grade chondrosarcoma) [Figure 4]. Areas of spindle-shaped cells having pleomorphic hyperchromatic nuclei (fibrosarcoma) were also seen [Figure 5]. There was an abrupt transition between these two tumor types. Hence, final diagnosis of DDCS of the proximal femur was given.
|Figure 1: X-ray of right hip joint showed an osteolytic lesion of right proximal femur|
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|Figure 2: Magnetic resonance imaging of right hip joint showed an osteolytic lesion with subtrochanteric fracture of right proximal femur|
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|Figure 3: Fine needle aspiration cytology showed chondroid material with atypical chondrocytes|
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|Figure 4: Lobules of cartilage having pleomorphic, hyperchromatic nuclei of chondrocytes (low-grade chondrosarcoma)|
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|Figure 5: Spindle-shaped cells having pleomorphic hyperchromatic nuclei (fibrosarcoma)|
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| Discussion|| |
The term DDCS was introduced by Dahlin and Beabout in 1971.  An essential histological feature of DDCS is an abrupt interface between the cartilaginous and noncartilaginous components. The hypothesis that the high-grade noncartilaginous tumor cell line arises in a long-standing low-grade cartilaginous tumor is often supported by the clinical course. Alternative hypotheses are that two malignant cell lines, with different capacities to differentiate, arise simultaneously or that the noncartilaginous sarcoma represents malignant transformation occurring in inflamed, but otherwise normal tissue adjacent to a cartilaginous tumor.  The most commonly involved sites are bones of the pelvis (the ilium is the most frequently involved bone), followed by the proximal femur, proximal humerus, distal femur, and ribs. In the long bones, it occurs in the metaphysis or diaphysis. The most frequently reported symptoms are pain, soft tissue masses, and pathologic fractures.  Radiographs are important not only for detection but also to decide on follow-up analysis with MRI or histology. DDCS may have a wide range of radiographic appearances. Radiographic studies include evaluation for the presence of bone destruction, cortical thickening, and cortical endosteal scalloping; the presence and pattern of periosteal reaction; matrix mineralization; the presence and features of soft tissue masses; pathologic fracture; and the presence of biomorphic features.  Localization in the axial skeleton and a size greater than 5 cm were found to be reliable predictors of malignancy.  MRI is used to depict the extent of intraosseous and soft tissue involvement.  On gross examination, the central part of the tumor showed blue-grey lobulated low-grade cartilaginous component and extraosseous gray-white higher grade component. Histologic examination of DDCS characteristically shows the presence of a well-differentiated chondrosarcoma juxtaposed to an anaplastic, nonchondroid sarcoma. The differentiated portion of the tumor consists most often of malignant fibrous histiocytoma or fibrosarcoma. Less commonly, however, osteosarcomatous or rhabdomyosarcomatous elements may also be present. There is abrupt demarcation between the two components. Binucleation is frequently seen. Permeation of cortical bone is an important characteristic. It is important to maintain a high level of suspicion when investigating and treating chondrosarcoma. The prognosis for patients with DDCS is improved by accurate preoperative diagnosis. It is important that biopsies should be representative of the entire tumor, and radiological and clinical features should be considered when interpreting tissue specimens. The most important factors affecting survival are early recognition of the radiographic features, adequate histological sampling, and wide-margin resection of the lesion. For all nonmetastatic chondrosarcoma, surgery is the only effective form of treatment; the most optimal type of surgical management is still debated.  Locally, this type of sarcoma is very aggressive and wide margins of excision are of the utmost importance in achieving control of local disease. Chondrosarcoma, in general, is resistant to chemotherapy, and anti-tumor drugs are rarely used in the treatment. However, adjuvant chemotherapy with cisplatin and doxorubicin was associated with improved survival in a few cases.  Radiotherapy can be considered in the case of incomplete resection, or when resection is not feasible or would cause unacceptable morbidity.  Metastases occur early and frequently involve the lungs, lymph nodes, and viscera.  DDCS has a poor prognosis; patients rarely surviving for more than 2 years.  Local recurrence has been reported in up to 50% of cases after excision, with much better control of local disease after radical amputation. Median survival has been as short as 6 months and 5 years rates of survival as low as 10-13%.  To conclude for the correct histopathological diagnosis, the biopsy sample should be adequate to visualize both cartilaginous and noncartilaginous sarcomatous component which helps to increase the survival of patients before the distant metastasis occurs.
| References|| |
Capanna R, Bertoni F, Bettelli G, Picci P, Bacchini P, Present D, et al.
Dedifferentiated chondrosarcoma. J Bone Joint Surg Am 1988;70:60-9.
Dahlin DC, Beabout JW. Dedifferentiation of low-grade chondrosarcomas. Cancer 1971;28:461-6.
Johnson S, Têtu B, Ayala AG, Chawla SP. Chondrosarcoma with additional mesenchymal component (dedifferentiated chondrosarcoma). I. A clinicopathologic study of 26 cases. Cancer 1986;58:278-86.
Staals EL, Bacchini P, Bertoni F. Dedifferentiated central chondrosarcoma. Cancer 2006;106:2682-91.
Geirnaerdt MJ, Hermans J, Bloem JL, Kroon HM, Pope TL, Taminiau AH, et al.
Usefulness of radiography in differentiating enchondroma from central grade 1 chondrosarcoma. AJR Am J Roentgenol 1997;169:1097-104.
Gelderblom H, Hogendoorn PC, Dijkstra SD, van Rijswijk CS, Krol AD, Taminiau AH, et al.
The clinical approach towards chondrosarcoma. Oncologist 2008;13:320-9.
Mitchell AD, Ayoub K, Mangham DC, Grimer RJ, Carter SR, Tillman RM. Experience in the treatment of dedifferentiated chondrosarcoma. J Bone Joint Surg Br 2000;82:55-61.
Mercuri M, Picci P, Campanacci L, Rulli E. Dedifferentiated chondrosarcoma. Skeletal Radiol 1995;24:409-16.
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]