Osteosarcoma and Undifferentiated Pleomorphic Sarcoma of Bone

Osteosarcoma and undifferentiated pleomorphic sarcoma (UPS) of the bone—formerly called malignant fibrous histiocytoma—are forms of bone cancer. Osteosarcoma usually starts in osteoblasts, which are a type of bone cell that become new bone tissue. Osteosarcoma is most common in adolescents and young adults, with about 440 cases diagnosed each year in those under the age of 19, according to the National Cancer Institute.

Having past treatment with radiation or chemotherapy can increase the risk of osteosarcoma. Other risk factors for osteosarcoma include having a certain change in the RB1 gene and having certain conditions such as Paget disease, Diamond-Blackfan anemia, Li-Fraumeni syndrome, and Werner syndrome.

UPS is a rare tumor that can form in the bone, but is much more common in soft tissue. It is treated like osteosarcoma.

Osteosarcoma and Undifferentiated Pleomorphic Sarcoma of Bone Treatment (PDQ®)

Source: National Cancer Institute