You are in: eMedicine Specialties > Orthopedic Surgery > NEOPLASMS FibrosarcomaArticle Last Updated: Mar 2, 2007AUTHOR AND EDITOR INFORMATIONSection 1 of 12
  Author: Ian D Dickey, MD, FRCSC, Adjunct Professor, Department of Chemical and Biological Engineering, University of Maine; Consulting Staff, Adult Reconstruction, Orthopedic Oncology, Department of Orthopedics, Eastern Maine Medical Center Ian D Dickey is a member of the following medical societies: American Academy of Orthopaedic Surgeons, British Columbia Medical Association, Canadian Medical Association, and Royal College of Physicians and Surgeons of Canada Coauthor(s): James Floyd, MD, Consulting Staff, Section of Orthopedic Surgery, Manatee Memorial Hospital Editors: Howard A Chansky, MD, Associate Professor, Department of Orthopedics and Sports Medicine, University of Washington Medical Center; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Sean P Scully, MD, PhD, Professor, Department of Orthopedics, University of Miami; Dinesh Patel, MD, FACS, Associate Clinical Professor of Orthopedic Surgery, Harvard Medical School; Chief of Arthroscopic Surgery, Department of Orthopedic Surgery, Massachusetts General Hospital; Harris Gellman, MD, Consulting Surgeon, Broward Hand Center, Voluntary Clinical Professor of Orthopedic Surgery and Plastic Surgery, Departments of Orthopedic Surgery and Surgery, University of Miami School of Medicine Author and Editor Disclosure Synonyms and related keywords: mesenchymal cell tumor, malignant fibroblasts, fibroblastic malignancy INTRODUCTIONSection 2 of 12
  Fibrosarcoma is a tumor of mesenchymal cell origin that is composed of malignant fibroblasts in a collagen background. It can occur as a soft-tissue mass or as a primary or secondary bone tumor. Fibrosarcoma was diagnosed much more frequently in the past; it is now more reliably distinguished histologically from similar lesions, such as desmoid tumors, malignant fibrous histiocytoma, malignant schwannoma, and high-grade osteosarcoma. The 2 main types of fibrosarcoma of bone are primary and secondary. Primary fibrosarcoma is a fibroblastic malignancy that produces variable amounts of collagen. It is either central (arising within the medullary canal) or peripheral (arising from the periosteum). Secondary fibrosarcoma of bone arises from a preexisting lesion or after radiotherapy to an area of bone or soft tissue. This is a more aggressive tumor and has a poorer prognosis. History of the ProcedureAs with all soft-tissue and bone sarcomas, the mainstay of treatment for fibrosarcoma has been complete excision with an adequate margin; this procedure became prevalent following the publication and wide acceptance of Enneking's surgical principles of musculoskeletal oncology, in the early 1980s. This surgery normally consists of resecting a cuff of normal tissue along with the tumor. ProblemAs with all sarcomas, the long-term survival and ultimate functional outcome of cancer treatment depend on many interrelated factors. Among these are the size and location of the tumor, its histologic grade, and the presence of metastatic disease (eg, pulmonary metastases). These factors are taken into account with careful evaluation (staging) of the tumor and determine the success of treatment in obtaining good local control and preventing subsequent disease spread. FrequencyFibrosarcoma represents only about 10% of musculoskeletal sarcomas and less than 5% of all primary tumors of bone. No known racial predilection exists. Fibrosarcoma of bone occurs slightly more commonly in men than in women. Fibrosarcoma of bone can be diagnosed in patients of any age, but it is diagnosed more commonly in patients in the fourth decade of life. It is usually located in the lower extremities, especially the femur and tibia. Fibrosarcoma of the soft tissues usually affects a wider age spectrum of patients than fibrosarcoma of the bone does, with an age range of 35-55 years. It often arises in the soft tissues of the thigh and the posterior knee. It is generally a large, painless mass deep to fascia and has an ill-defined margin. An infantile form (in children <10 y) of fibrosarcoma exists. Unlike fibrosarcoma in adults, it has an excellent prognosis—even in the face of metastatic disease at presentation—when treated with a combination of neoadjuvant and adjuvant chemotherapy and resection. EtiologyFibrosarcoma, like other soft-tissue sarcomas, has no definite cause. Current research indicates that many sarcomas are associated with genetic mutations. The more common genetic defects include allele loss, point mutations, and chromosome translocations. See Pathophysiology for a discussion of associated conditions. PathophysiologyNo definite cause of fibrosarcoma is known, although genetic mutations may play a role. Several inherited syndromes are associated with sarcomas. For example, patients with multiple neurofibromas may have a 10% lifetime risk of developing a neurosarcoma or a fibrosarcoma. The occurrence of fibrosarcoma in conjunction with metallic implants used for fracture fixation or joint reconstruction has been reported, albeit very rarely. The cause of this transformation is unknown. Fibrosarcoma has also been noted to arise from preexisting lesions, such as bone infarcts and lesions associated with fibrous dysplasia, chronic osteomyelitis, and Paget disease, as well as in previously irradiated areas of bone. This form of fibrosarcoma is very aggressive and is associated with a much poorer outcome than is the primary fibrosarcoma of bone. ClinicalSarcomas involving bone often present with pain and swelling after a long duration of symptoms. They may even grow large enough to threaten the structural integrity of the bone and cause pathologic fracture as the initial presentation. Generally, lesions that involve more than 50% of the bone cortex, that are larger than 2 cm, or that involve the medial calcar of the femur are associated with the greatest risk of fracture. A prior history of bone infarct, irradiation, or other such risk factors should alert the physician to the possibility of a secondary fibrosarcoma. Soft-tissue sarcomas most often present as painless masses. The time to presentation, however, is often shorter than with lesions involving bone. Because these lesions frequently arise deep to the muscular fascia, they may become extremely large tumors prior to diagnosis. Most lesions occur around the knee, in the proximal femur and hip region, or in the proximal arm. Findings are nonspecific and can vary from a fixed, firm mass to a localized area of tenderness. Neurologic or vascular changes are late findings and indicate extensive disease involvement. Differential diagnoses include the following:
INDICATIONSSection 3 of 12
To obtain local control, surgical resection with a cuff of normal tissue (wide margins) and reconstruction of the subsequent defect are necessary. RELEVANT ANATOMYSection 4 of 12
See Introduction, Clinical. CONTRAINDICATIONSSection 5 of 12
Surgical treatment (including biopsy) of fibrosarcoma should not proceed unless complete patient care is available. Complete care includes biopsy and interpretation of biopsy findings, access to oncologists and radiation oncologists, and definitive resection. Fibrosarcomas should be removed by trained orthopedic oncologists who can provide a state-of-the-art treatment program; this would involve a team of well-trained specialists with advanced experience in treating these tumors. WORKUPSection 6 of 12
Lab Studies
Imaging Studies
Diagnostic Procedures
Histologic FindingsFibrosarcomas are tumors of malignant fibroblasts and collagen. They vary in histologic grade. Well-differentiated forms have multiple plump fibroblasts with deeply staining nuclei in a rich collagen background. Intermediate-grade tumors have the typical herringbone pattern, showing the diagnostic parallel sheets of cells arranged in intertwining whorls. A slight degree of cellular pleomorphism exists. High-grade lesions are very cellular, with marked cellular atypia and mitotic activity. The matrix is sparse. No malignant osteoid formation should be present. Higher grades are extremely anaplastic and pleomorphic, with bizarre nuclei that bring to mind the histologic features of malignant fibrous histiocytoma. In fact, some pathologists believe that the division between malignant fibrous histiocytoma, high-grade osteosarcoma, and fibrosarcoma may be artificial. StagingSeveral staging systems are used for tumors of the musculoskeletal system. The 2 most common systems are those of the Musculoskeletal Tumor Society and of the American Joint Committee on Cancer. Both systems include histologic grade, tumor site, and presence or absence of metastasis. Other factors that may be important in staging are the size and depth of the tumor. TREATMENTSection 7 of 12
Medical therapyAdjunctive therapy, such as radiation treatment and chemotherapy, can improve local control and may make the appearance of clinically evident metastatic disease less likely. The use of chemotherapy is controversial, but chemotherapy is generally used in bone lesions. Radiation therapy is used in conjunction with surgery for soft-tissue fibrosarcomas, with or without chemotherapy. Surgical therapyIn general terms, treatment of fibrosarcoma involves a combination of adequate local tumor control and avoidance or treatment of distant disease. Many factors are involved and contribute to the ultimate prognosis. To obtain local control, surgical resection with a cuff of normal tissue (wide margins) and reconstruction of the subsequent defect are necessary. Follow-upAs with all sarcomas of the musculoskeletal system, successful treatment of fibrosarcoma must be accompanied by an organized plan for clinical follow-up. This often involves a schedule of repeat examinations and diagnostic studies. Patients often are monitored for a minimum of 5 years. At preset intervals, the patient is reexamined, and plain radiographs of the involved site are obtained. Repeat staging studies of the local area and of the chest also are performed. COMPLICATIONSSection 8 of 12
Local recurrence may occur in up to 60% of cases and is the reason that postoperative radiation, preoperative radiation, or both are often recommended. Local recurrence is reduced to about 25% when postoperative irradiation is used. OUTCOME AND PROGNOSISSection 9 of 12
If all grades are included, primary fibrosarcoma of the bone has a worse prognosis than osteosarcoma, with a 5-year survival rate of 65%. In high-grade primary fibrosarcoma, the 10-year survival rate is less than 30%. Secondary fibrosarcoma is associated with a very poor outcome, the survival rate at 10 years being less than 10%. For congenital fibrosarcoma of bone in children, the prognosis (which is related to age and to time to diagnosis) is much better, with the disease having long-term survival rates of higher than 50%. Soft-tissue fibrosarcoma is associated with a 40-60% survival rate at 5 years. The infantile form has an even better 5-year survival rate, in excess of 80%. FUTURE AND CONTROVERSIESSection 10 of 12
Continued advances in the molecular biology of sarcomas may further elucidate the very distinct clinical behavior of the various types of fibrosarcoma and ultimately provide better solutions to their respective treatment. MULTIMEDIASection 11 of 12
REFERENCESSection 12 of 12
Article Last Updated: Mar 2, 2007 | |||||||||||||||||||
