Diagnosis

Doctors use many tests to diagnose cancer and determine if it has metastasized (spread). Some tests may also determine which treatments may be the most effective. For most types of cancer, a biopsy is the only way to make a definitive diagnosis of cancer. If a biopsy is not possible, the doctor may suggest other tests that will help make a diagnosis. Imaging tests may be used to find out whether the cancer has metastasized. Your child’s doctor may consider these factors when choosing a diagnostic test:

• Age and medical condition
  
  
• The type of cancer suspected
  
  
• Severity of symptoms
  
  
• Previous test results

In addition to a physical examination, the following tests may be used to diagnose osteosarcoma. It is recommended that a health care team with experience in the diagnosis and treatment of bone tumors perform these tests.

Imaging tests

X-ray. An x-ray is a picture of the inside of the body. The doctor will take an x-ray of the area where the lump or swelling occurs. Osteosarcoma usually shows certain common characteristics on an x-ray.

Computed tomography (CT or CAT) scan. A CT scan creates a three-dimensional picture of the inside of the body with an x-ray machine. A computer then combines these images into a detailed, cross-sectional view that shows any abnormalities or tumors. Sometimes, a contrast medium (a special dye) is injected into a patient’s vein to provide better detail.

Magnetic resonance imaging (MRI). An MRI uses magnetic fields, not x-rays, to produce detailed images of the body. A contrast medium may be injected into a patient’s vein to create a clearer picture. MRI creates more detailed pictures than CT scans and can sometimes detect a smaller tumor. Also, MRI provides more exact pictures of the tumor and the surrounding normal tissue; this can help the orthopedic surgeon (a doctor who specializes in surgery on the bones) plan surgery to remove the tumor-containing area of bone with a portion of the surrounding healthy tissue (called a margin).

Bone scan. A bone scan uses a radioactive tracer to look at the inside of the bones. The tracer is injected into a patient’s vein. It collects in areas of the bone and is detected by a special camera. Healthy bone appears gray to the camera, and areas of injury, such as those caused by cancer, appear dark. It is also normal that areas where new bone is being formed, such as the growth plates (called epiphyses), appear dark.

Arteriogram (also called angiogram). A doctor injects a small amount of a contrast medium into an artery that can be detected by x-ray. A surgeon may use this test to help plan surgery.

Biopsy. A biopsy is the removal of a small amount of tissue for examination under a microscope. Other tests can suggest that cancer is present, but only a biopsy can make a definitive diagnosis. The sample removed from the biopsy is analyzed by a pathologist (a doctor who specializes in interpreting laboratory tests and evaluating cells, tissues, and organs to diagnose disease). A doctor who specializes in bone tumors should perform the biopsy, which typically involves surgery. Doctors may analyze the genes in the cancer cells to distinguish osteosarcoma from other types of cancer.

Learn more about what to expect when having common tests, procedures, and scans.

Find out more about common terms used during a diagnosis of cancer.