Common diagnostic medical tests for children with solid tumors
Biopsy. This is the process of removing a small amount of tissue, such as a piece of tumor. A pathologist uses a microscope to look at the sample, which is also called a biopsy. A definite diagnosis of a solid tumor requires a biopsy. Certain brain tumors are exceptions and do not need a biopsy to be diagnosed.
Blood chemistries. This test requires a small sample of your child’s blood. Certain blood chemistry tests tell your doctors whether your child's kidney and liver are working normally. Other tests show whether your child’s nutrition is good enough.
Blood coagulation test. This test requires a small sample of your child’s blood. Coagulation tests show if the blood is clotting like it should. Your child might get a blood coagulation test before surgery to make sure he or she will not bleed too much. This test is also used to check bleeding or bruising. Types of coagulation tests include fibrinogen tests or prothrombin tests.
Bone marrow aspirate and biopsy. These two tests are often done at the same time. A sample of the liquid part of bone marrow is removed in a bone marrow aspiration. A sample of the solid part of bone marrow is removed in a bone marrow biopsy. A pathologist uses a microscope to look at both samples. It is common for the marrow to be removed from the pelvic bone by the hip. These tests show whether a solid tumor has spread into the bone marrow cavity.
Bone scan. See nuclear medicine bone scan.
Chemistry panel. See blood chemistries.
Complete blood count (CBC). This test requires a small sample of your child’s blood. This test measures all of the following:
- Number of red blood cells, the cells that have hemoglobin and carry oxygen
- Number of white blood cells, which help fight infection
- Number of platelets, which help the blood clot
- Amount of hemoglobin, the protein that carries oxygen in the blood
- Hematocrit, which is the percentage of blood volume taken up by red blood cells and the amount of hemoglobin in them
- A CBC shows whether your child has anemia, a low platelet count or an infection.
Computed tomography scan (CT or CAT scan). This is a type of imaging test. Your child will not need to be cut or have any medical instruments inserted for this test. However, your child does need to be very still while the test is in process.
The CT scan uses special X-ray equipment to create a 3-D picture of the inside of your child’s body. The scan shows the presence of a tumor. It shows where a tumor is, its shape and its size. It can also show the blood vessels that feed the tumor. These scans are helpful before surgery. CT scans help guide doctors during a biopsy. This is called a CT-guided biopsy.
CT scans can also be used to show how a tumor is responding to treatment.
CT-guided biopsy. See computed tomography scan.
Lumbar puncture. See spinal tap.
Magnetic resonance imaging (MRI). This is a type of imaging test. Your child won’t need to be cut or have any tools inserted for this test. However, your child does need to be very still while the test is in process.
Using magnetic fields, an MRI makes detailed pictures of the structure of organs and the blood flow in and out of them.
An MRI shows the location of a tumor. It also shows the size of the tumor, and if it is safe to remove with surgery. An MRI can sometimes show whether a brain tumor is cancerous or not. MRIs also help doctors plan surgery and radiation therapy.
Metabolic profile. See blood chemistries.
Nuclear medicine bone scan. This is a type of imaging test. This test has two parts. First, your child gets a small amount of radioactive material through an IV or by swallowing it like a pill. This material is also called a radionuclide, radiopharmaceutical, radiotracer or tracer.
Then you wait at least 2 hours.
When the tracer is absorbed, your child lies on a table and slides into the “donut hole” of the scanner. The scanner has special cameras in it that detect the radiation. The cameras rotate around your child’s body to make 3-D pictures.
Nuclear medicine bone scans help show whether the tumor has spread to the bones.
Positron emission tomography (PET) scan. This is an imaging test. A PET scan is sometimes done with a CT scan. There are two parts to this test. First, your child will get an IV with a small amount of radioactive sugar called a tracer.
About an hour later, your child slides into the large tunnel-shaped PET scanner. A PET scan shows how organs, such as the bones, brain, kidneys and liver, are working. A computer turns the signal from the tracer into 3-D pictures.
Sonogram. See ultrasound.
Spinal tap. This is the process of taking out a sample of spinal fluid. A pathologist uses a microscope to check the fluid for cancer cells. This test shows whether the tumor has spread into the spinal fluid. A spinal tap also shows if cancer has spread into the tissue around the brain and spinal fluid, which is called the meninges. Your child’s doctor may set up a spinal tap if your child has a tumor in the sinuses or near the eye orbit.
Ultrasound. Your child won’t need to be cut or have any medical instruments inserted for this test. Using high-frequency sound waves, an ultrasound machine makes pictures called sonograms. These machines get pictures of soft tissues that do not show up well on X-rays.
An ultrasound can tell the difference between a solid tumor and a fluid-filled cyst. But an ultrasound cannot tell if the solid tumor is cancerous. Your child’s doctor may also use ultrasound during a biopsy to help locate the tumor.
Urinalysis. This test requires a small sample of your child’s urine. The analysis shows whether your child's kidneys are working well and whether there is blood in the urine. A urine test shows the presence of a substance called catecholamines, which is a sign of neuroblastoma.