A fibrosarcoma is a rare, malignant (cancerous) tumor of the cells that make up connective tissue. A fibrosarcoma may develop from a fibroma (a benign tumor of connective tissue) or it may be malignant from the start.
A fibrosarcoma most often develops in tissues around the muscles in a limb but can also affect a bone or the cells around nerve fibers (see also bone cancer. The tumor can spread to damage nearby structures.
A fibrosarcoma causes a localized swelling, which may not be noticed at first, depending on its site and how deep it is. Occasionally, widened veins appear on the skin over the growth; the fibrosarcoma may feel warm or may pulsate.
Treatment is by surgical removal or radiotherapy; this may be only temporarily successful if cells from the tumor have spread via the bloodstream to start growths elsewhere in the body.