Usually found in the areas around bones or in soft tissues, fibrosarcoma is a form of a malignant tumor that results from fibroblasts, or cells that produce the connective tissue, such as collagen. Fibrosarcomas can form in muscles, connective tissues, blood vessels, the joints, and in fat. Fibrosarcomas of the soft tissues typically occur in the trunk of one’s body and in the arms and legs. These types of fibrosarcomas are quite rare, with about 500 new cases reported on an annual basis.
When fibrosarcomas present in the bone, they are usually found in the long bones in the bone marrow where the collagen is formed. The bones in which fibrosarcomas are typically found are in the legs, the arms, the hip, and the pelvis.
Sarcomas of the bone are rare and account for roughly 0.2 percent of all new cancer cases reported each year. The most common types of bone cancer are osteosarcoma and Ewing’s sarcoma. Fibrosarcoma is less common, arising from spindle cell neoplasms.
Fibrosarcomas are generally found in people ranging in age from 25-79. The peak age for this type of tumor is between 55 and 69. While they occur equally among men and women, they are rare in children. There is a form of fibrosarcoma called infantile fibroscaroma, also known as congenital fibrosarcoma or juvenile fibrosarcoma. This is a highly unique condition. Through microscopic evaluation, it runs consistent with fibrosarcomas seen in adults. However, infantile fibrosarcomas recognize a more positive outlook, with a five-year survival rate between 83 and 94 percent.
While the exact cause of fibrosarcoma remains unclear, there is indication that genetics plays a role. Researchers have studied a handful of families that have several members from one generation who have sustained soft tissue sarcomas. Further, there may be a link between soft tissue sarcomas and the onset of other types of cancer.
When fibrosarcomas are present, the patient may notice a painless or tender mass in an arm or a leg, or even in the trunk. The pain or soreness could be caused by a suppressed nerve or muscle.