|
Year |
2002 |
|---|---|
|
Question Number |
166. |
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Category |
Orthopaedic Disease |
Question
A 62 year old woman has a painful swelling in her left hip region. Examination reveals a palpable mass. Staging work-up shows this to be an isolated lesion. A plain radiograph, MRI scans, and a biopsy specimen are shown in figures 44a-d. management should consist of
1- Wide excision, radiation therapy, and chemotherapy
2- Wide excision and radiation therapy
3- Wide excision and chemotherapy
4- Wide excision only
5- Prophylactic stabilization and radiation therapy
Figures
Answer (click for answer)
Preferred response: (4) Wide excision only.
Chondrosarcoma of bone is a malignant tumor arising from cartilage cells. Although endochondral ossification within the tumor may occur, no true neoplastic osteoid or bone is formed. Chondrosarcomas may be classified as primary (arising de novo) or secondary (arising from a precursor lesion such as an osteochondroma or enchondroma). They may be central (medullary) or peripheral (on the surface of the bone). Histologically, they may be low, medium, or high grade, and this correlates well with their biological aggressiveness. Low grade chondrosarcoma is most difficult to distinguish from enchondroma. In addition, chondrosarcomas may vary considerably in their histology from one part of the lesion to another. Thus to avoid sampling errors, generous open biopsy is required. The biological behavior is determined by the most aggressive part of the tumor.
Like osteogenic sarcoma, variants of chondrosarcoma have been found, including clear cell chondrosarcoma, a low grade lesion with a wide age range, more common in males and usually located in the ends of long bones; periosteal chondrosarcoma, a low grade lesion usually of young males most commonly involving the distal femur; mesenchymal chondrosarcoma, a high grade, highly lethal lesion with biphasic histology; and dedifferentiated chondrosarcoma, a high grade transition of chondrosarcoma (of any grade) into a lesion of different histological type (such as fibrosarcoma, malignant fibrous histiocytoma, or osteogenic sarcoma). This dedifferentiation has been found to occur in approximately 10% of chondrosarcomas.
Chondrosarcoma typically occurs in adults 30 to 60 years of age, although childhood chondrosarcoma does occur and appears to be more aggressive than the adult form. The femur, pelvis, tibia, humerus, scapula, and ribs are the most common sites. Patients usually have a long history of pain or a mass or both. Roentgenograms show a destructive lesion often with intralesional calcification, endosteal scalloping and cortical thinning or expansion. Proper staging requires computed tomography and magnetic resonance imaging of the affected part to define the anatomical setting, and a bone scan and computed tomography of the lungs to determine distant spread. Biopsy exposure should be carefully planned so that wide resection of the tract can be accomplished along with the definitive resection. Chondrosarcomas notoriously seed soft tissues after biopsy or inadequate resection.
Low grade and intermediate grade lesions require wide margins for local control. High grade lesions should have radical margins. The adequacy of surgical treatment has been demonstrated to determine both the incidence of local recurrence (persistence) and survival. High grade lesions should probably be treated with systemic chemotherapy, although this is controversial.
Although chondrosarcoma is generally believed to be radioresistant, Harwood, Krajbich, and Fornasier have found radiotherapy to be beneficial when the tumor could not be resected or when resection was inadequate.
Reference: Campanacci M, Ennekin WF: Central chondrosarcomas, in Campanacci M, Enneking WF (eds): Bone and soft tissue tumors. NY, NY< Springer-Verlag, 1999; 283-318.
McCarthy EF, Frassica FJ: Primary bone tumors, in McCarthy EF, Frassica FJ (ed): Pathology of bone and joint disorders with clinical and radiographic correlation. Phila, PA WB Saunder, 1998; 235-44.
Canale ST. Campbell’s operative orthopedics, 9th ed. 1998; 718-22.