👉 Fibrosarcoma is a type of cancer that typically affects bones, but it can also affect other parts of the body. It's also called "bone sarcoma" or "fibrous sarcoma." The exact cause isn't known, but there are some theories about how fibrosarcomas form. Some people believe they might be caused by a genetic mutation in genes that help form the cells of bone and cartilage. Other scientists think it could be related to stress or infections.