Cancer:
Most bone tumors are non-cancerous (benign), but some are cancerous (malignant). Benign tumors are usually not life threatening, but malignant tumors can spread cancer cells (metastasize) throughout the body via the blood or lymphatic  systems. Cancer that begins in bone (primary bone cancer) is different from cancer that begins somewhere else in the body and spreads to bone (secondary bone cancer). Primary bone cancer affects more males than females, and is rare. In 2001, doctors were expected to diagnose about 2,900 new cases of bone and joint cancer. Some types of bone cancer affect mostly teenagers. Three main types of bone cancer are involved in about 75 percent of all cases:

Osteosarcoma, the most common bone cancer, usually develops in tissues in the growing bones of children and adolescents, age 10-25. It typically occurs around the knee. Other common locations include the upper leg and upper arm. Osteosarcoma can also affect the elderly in association with Paget disease. Chondrosarcoma develops in cartilage and usually affects adults, age 50-60. The upper leg, pelvis and shoulder are common sites.Ewing's sarcoma may begin in immature cells in the bone marrow and usually affects children and adolescents, age 10-20. The upper leg, arm, pelvis and ribs are the main locations.

Diagnosis and treatment:
See your doctor as soon as possible for diagnosis and treatment if you think you might have a bone tumor. The doctor will collect detailed information about your general health and the tumors type, size, location and possible extent of cancer (stage).

Medical history and physical exam:
Give the doctor your complete medical history including your age and details about any previous tumors or cancers. Does anyone in your family have a history of cancer? How is your health overall? Your doctor will physically examine you, focusing on the tumor mass, tenderness in bone and any impact on joints and/or range of motion. In some cases, the doctor may want to examine other parts of your body to rule out cancers that can spread to bone.

Imaging and tests:
Your doctor will probably take a series of X-rays to see the tumors exact location, level of activity and other characteristics. If the tumor looks like it might be cancer, you may also need additional imaging studies such as MRI (magnetic resonance imaging), CT scan (computed tomography) or ultrasonography plus laboratory tests on blood and urine samples to provide more details about the extent of disease.

Biopsy:
Your doctor will probably need to remove a tissue sample (biopsy) from the tumor to examine by microscope. Biopsy can reveal the presence of cancer cells, the type of tumor and its degree of malignancy (grade). Among various methods of biopsy are:

1) Needle biopsy: The doctor inserts a needle into the tumor to remove small or larger amounts of tissue. This may be performed with local anesthesia in the office or with CT scan guidance with a radiologist.

2) Surgical biopsy: The doctor opens the skin to remove part of or the entire tumor. This is usually performed under general anesthesia in an operating room.

Benign tumors
Some common benign tumors include giant cell tumor, unicameral bone cyst, osteoid osteoma and benign cartilage tumors. In many cases, benign bone tumors need no treatment other than observation. Certain benign tumors can become malignant and metastasize. Sometimes, your doctor may recommend removing the tumor (excision) or using other treatment techniques to reduce the risk of fracture and disability. Some tumors may come back after removal.

Malignant tumors
You might want to get a second opinion to confirm any diagnosis of a malignant bone tumor. If you have bone cancer, your treatment team may include several specialists (i.e., radiologist, chemotherapist, pathologist, surgeon or orthopaedic oncologist). Treatment goals include curing the cancer and preserving bodily functions. Doctors often combine several methods of treatment for malignant bone tumors depending upon various factors including whether the cancer has spread.

Localized stage cancer cells are contained to the tumor and surrounding area.

Metastatic stage cancer cells have spread elsewhere in the body. This stage is more serious and harder to cure.

Local treatments include surgery and radiation therapy:

Limb salvage surgery removes the cancerous section of bone while preserving nearby tendons, nerves and blood vessels. If possible, the doctor will excise the entire tumor and a margin of healthy tissue around it. He or she will replace the excised bone and joint with a bone transplant or a metallic replacement (prosthesis).

Amputation removes all or part of an arm or leg when the tumor is large and/or nerves or blood vessels are involved.
Radiation therapy uses high-dose X-rays to kill cancer cells and shrink tumors.
Additional treatments are used for cancer that has spread:
Chemotherapy uses drugs to kill cancer cells. You take it by pill or needle injection into a vein or muscle.

After treatment
When treatment for a bone tumor is finished, you may need more X-rays and other imaging studies to confirm that it is actually gone. You may need to have regular doctor visits and tests every few months. When the tumor disappears, its important to monitor your body for its possible return (relapse).