Osteosarcoma and malignant fibrous histiocytoma (MFH) of the bone are diseases in which malignant (cancer) cells form in bone.
Osteosarcoma usually starts in osteoblasts, which are a type of bone cell that becomes new bone tissue. Osteosarcoma is most common in teenagers. It commonly forms in the ends of the long bones of the body, which include bones of the arms and legs. In children and teenagers, it often forms in the bones near the knee. Rarely, osteosarcoma may be found in soft tissue or organs in the chest or abdomen.
Osteosarcoma is the most common type of bone cancer. Malignant fibrous histiocytoma (MFH) of bone is a rare tumor of the bone. It is treated like osteosarcoma.
Ewing sarcoma is another kind of bone cancer, but it is not covered in this summary. See the PDQ summary about for more information.
Having past treatment with radiation can increase the risk of osteosarcoma.
Anything that increases your risk of getting a disease is called a risk factor. Having a risk factor does not mean that you will get cancer; not having risk factors doesn’t mean that you will not get cancer. Talk with your child's doctor if you think your child may be at risk. Risk factors for osteosarcoma include the following:
Signs and symptoms of osteosarcoma and MFH include swelling over a bone or a bony part of the body and joint pain.
These and other signs and symptoms may be caused by osteosarcoma or MFH or by other conditions. Check with a doctor if your child has any of the following:
- Swelling over a bone or bony part of the body.
- Pain in a bone or joint.
- A bone that breaks for no known reason.
Imaging tests are used to detect (find) osteosarcoma and MFH.
Imaging tests are done before the biopsy. The following tests and procedures may be used:
- Physical exam and history: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient’s health habits and past illnesses and treatments will also be taken.
- X-ray: An x-ray of the organs and bones inside the body. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.
- CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.
- MRI (magnetic resonance imaging): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body. This procedure is also called nuclear magnetic resonance imaging (NMRI).
A biopsy is done to diagnose osteosarcoma.
Cells and tissues are removed during a biopsy so they can be viewed under a microscope by a pathologist to check for signs of cancer. It is important that the biopsy be done by a surgeon who is an expert in treating cancer of the bone. It is best if that surgeon is also the one who removes the tumor. The biopsy and the surgery to remove the tumor are planned together. The way the biopsy is done affects which type of surgery can be done later.
The type of biopsy that is done will be based on the size of the tumor and where it is in the body. There are three types of biopsy that may be used:
The following tests may be done on the tissue that is removed:
- Fine-needle aspiration (FNA) biopsy: The removal of tissue or fluid using a thin needle.
- Core biopsy: The removal of tissue using a wide needle.
- Incisional biopsy: The removal of part of a lump or a sample of tissue that doesn't look normal.
- Excisional biopsy: The removal of an entire lump or area of tissue that doesn’t look normal.
- Light and electron microscopy: A laboratory test in which cells in a sample of tissue are viewed under regular and high-powered microscopes to look for certain changes in the cells.
- Cytogenetic analysis: A laboratory test in which cells in a sample of tissue are viewed under a microscope to look for certain changes in the chromosomes.
- Immunocytochemistry study: A laboratory test in which a substance such as an antibody, dye, or radioisotope is added to a sample of cancer cells to test for certain antigens. This type of study is used to tell the difference between different types of cancer.
Certain factors affect prognosis (chance of recovery) and treatment options.
The prognosis (chance of recovery) is affected by certain factors before and after treatment.
The prognosis of untreated osteosarcoma and MFH depends on the following:
After osteosarcoma or MFH is treated, prognosis also depends on the following:
- Where the tumor is in the body and whether tumors formed in more than one bone.
- The size of the tumor.
- Whether the cancer has spread to other parts of the body and where it has spread.
- The type of tumor (based on how the cancer cells look under a microscope).
- The patient's age at diagnosis.
- Whether the patient has certain genetic diseases.
Treatment options for osteosarcoma and MFH depend on the following:
- How much of the cancer was killed by chemotherapy.
- How much of the tumor was taken out by surgery.
- Whether chemotherapy is delayed for more than 3 weeks after surgery takes place.
- Whether the cancer has recurred (come back) within 2 years of diagnosis.
- Where the tumor is in the body.
- The size of the tumor.
- The stage of the cancer.
- Whether the bones are still growing.
- The patient's age and general health.
- The desire of the patient and family for the patient to be able to participate in activities such as sports or have a certain appearance.
- Whether the cancer is newly diagnosed or has recurred after treatment.