Fibrosarcoma represents only about 10% of musculoskeletal sarcomas and fewer than 5% of all primary tumors of bone. It 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 years) 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. [7, 8, 9, 10]
Fibrosarcoma of bone occurs slightly more commonly in men than in women. No known racial predilection exists.
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Although fibrosarcoma of bone can arise anywhere, it is found most commonly about the knee and femur. The radiograph here shows a typical appearance of a lesion in bone.
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Most pathologists describe the histologic picture of fibrosarcoma as a herringbone pattern. It is an interlacing pattern of sheets of spindle-shaped fibroblasts in a collagen background. This pattern is very distinctive and usually confirms the diagnosis of fibrosarcoma.
