Imaging Tests
A physician will usually order imaging tests such as an x-ray, which will allow the doctor to see any unusual bone growths. This may be followed by a bone scan, to see if there are other abnormal areas in the skeleton. Before a bone scan, a small amount of "tracer" material is injected into a vein. After a few hours, the tracer material, which is slightly radioactive, collects in places where there is new bone growth. A CT (computed tomography) or MRI (magnetic resonance imaging) scan is often ordered to show the exact size and shape of the suspected bone tumor, and to determine if it has invaded surrounding tissue or the bone marrow space.
A PET (positron emission tomography) scan is also used in bone cancer diagnosis. Unlike other imaging techniques that focus on a precise area of the body, PET scans have the ability to show cancer growth throughout the whole body. PET and CT scans can be used in combination to pinpoint the exact location of cancer.
Biopsy
Finally, a biopsy of the suspicious bone tissue is needed to make a definite diagnosis. If the tumor is small enough, the doctor may remove the entire tumor, then analyze samples of it under a microscope to see if it is cancerous. This procedure is called an excisional biopsy. In other cases, the doctor may make a small opening in the skin and remove just a small part of the tumor for analysis -- an open biopsy. Or the doctor may do a needle biopsy, in which a sample of the tumor is removed through the skin using a needle.
It is very important that the biopsy be performed by an experienced and skilled surgeon, because an improperly performed biopsy may limit treatment options later.
A pathologist examines the biopsy samples to determine whether or not the tissue is cancerous, and if it is, to identify the exact type of cancer. Determining the exact type of cancer is critical, because not all types of bone cancer respond to the same kinds of treatment.
