Diagnosis

Doctors use many tests to diagnose cancer and determine if it has metastasized. 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 EFT:

Blood tests. A complete blood count (CBC) is a blood test done to count the number of each type of blood cells. Abnormal levels of white blood cells, red blood cells, and platelets can indicate that cancer has spread. The doctor may also check liver and kidney function and look for high levels of a particular blood enzyme (lactate dehydrogenase, or LDH), which sometimes helps to determine the presence of cancer in the body.

Imaging tests

X-ray. An x-ray is a picture of the inside of the body. For instance, a chest x-ray can help doctors determine if the cancer has spread to the lungs. Doctors can usually find bone tumors with 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 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.

Positron emission tomography (PET) scan. A PET scan is a way to create pictures of organs and tissues inside the body. A small amount of radioactive substance is injected into a patient’s body and absorbed by the organs or tissues being studied. This substance gives off energy that is detected by a scanner, which produces the images. A PET scan may be performed to help determine whether the tumor has spread to other parts of the body.

Surgical tests

Biopsy. A biopsy is the removal of a small amount of tissue for examination under a microscope. An orthopedic oncologist (a doctor who specializes in cancers of the musculoskeletal system) who has experience with EFT should perform the biopsy of a tumor in the arm or leg. The doctor may take a sample of the tumor itself, a sample of the bone marrow, or both. Other tests can suggest that cancer is present, but only a biopsy can make a definite 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).

Bone marrow aspiration. For this test, a small amount of bone marrow is removed with a needle from the hip bone and examined under a microscope. The child's skin is numbed with a local anesthetic during the procedure.

Laboratory tests

Using the tissue sample obtained from the biopsy, the doctor can conduct other laboratory tests to learn more about the cancer.

Immunohistochemistry. A test to detect EFT cells in tissue.

Cytogenetics test and reverse transcription polymerase chain reaction test (RT-PCR). Tests to determine if the genetic changes that characterize EFT cells are present in the sample.