Diagnosis

Testing a sample of your child’s blood, other body fluids or tissue helps diagnose many types of blood disorders and cancers. Depending on your child’s symptoms, their doctor may order tests to assess:

• How many cells of each type are moving through the bloodstream and what they look like (complete blood count or CBC)
• Chemicals in the blood that may be signs of disease and tell the health of different organs (blood chemistry)
• Substances that are found in higher levels in people with cancer (tumor markers)
• The body’s ability to form a blood clot (clotting studies)
• Levels of inflammation in the body (inflammatory markers)
• Different types of hemoglobin (hemoglobin electrophoresis)

We may take pictures of inside your child’s body (imaging studies):

• To look for tumors or places where cancer is active
• If your child has a blood disorder that may cause problems with their bones, lungs, brain or kidneys

We use the least amount of radiation possible while making the best image.

Pictures may be made using:

• X-rays
• CT (computed tomography) scan
• MRI (magnetic resonance imaging) scan
• PET (positron emission tomography) scan
• Bone scan
• MIBG (metaiodobenzylguanidine) scan
• Ultrasound
• Tests to check blood flow in vessels (vascular imaging) 
• Sound waves to make an image of the heart (echocardiogram)
• Radioactive iodine scan

As we treat your child, we may do imaging studies to check the effects of treatment.

• Our team uses state-of-the-art tests like molecular profiling and next-generation sequencing (NGS) for some types of cancer. Molecular profiling looks for cancer biomarkers, which may be DNA, RNA or a protein linked to a specific type of cancer. NGS quickly examines stretches of DNA or RNA for changes. Gene sequencing figures out the exact order of the genetic material in a strand of DNA.
• To learn about your child’s cancer, we also use standard diagnostic tests such as fluorescence in situ hybridization (FISH), immunohistochemistry, cytogenetics and flow cytometry.
• All of these tests help your care team find what’s different about your child’s cancer, confirm the subtype and personalize treatment for your child.
• We will give you all the information we can about your child’s tumor. We will also explain how the information may be used now or in the future.
• We often use advanced diagnostics to track how your child is responding to treatment. This lets us know sooner if a different approach is needed.

A biopsy is when a doctor removes a sample of body tissue so that it can be studied under the microscope by doctors trained to diagnose disease (pathologists). Often, they will do special tests to help tell the type of cells and make a diagnosis. This is important to identify the specific type of tumor and help plan treatment.

Our doctors who do biopsies have special training to perform the procedure. They are very careful to do the biopsy safely and to collect enough tissue to help make the diagnosis. We give your child medicine so they do not feel pain during the biopsy. 

Seattle Children’s doctors use equipment and techniques designed for children and teens. They will recommend the best biopsy method for your child. Sometimes an interventional radiologist (IR) uses imaging tools to find a tumor and sample the tissue with needles. In other cases a surgeon does the biopsy because the tissue cannot be reached by a needle or more tissue is needed. Sometimes, IR doctors will mark tissue with special dyes or wires so that surgeons can remove it in the operating room.

This test can be helpful in diagnosing cancer and bone marrow failure conditions. It helps doctors:

• Identify if there is a cancer that started in the bone marrow (leukemia)
• Tell if cancer has spread to the bone marrow
• See how well your child’s bone marrow is making red blood cells and understand what might be causing a bone marrow failure condition

Your child’s doctor will:

• Place a hollow needle into your child’s hip bone and suck out (aspirate) a small sample of liquid bone marrow
• Place a different needle into the bone to remove a small solid sample of bone marrow (biopsy)

Your child will get medicine to make them sleep and stay still during the procedure.

A pathologist will look at the bone marrow under a microscope. We may do other tests of your child’s bone marrow to learn more about how well it makes blood and immune system cells.

A lumbar puncture  is a way to collect cerebrospinal fluid (CSF) from your child’s spinal column. This is also called a spinal tap. The fluid is checked for cancer cells or other signs of disease.

Most children get medicine to make them sleep and stay still during the procedure. Then the doctor places a needle between 2 bones in the spine and collects a small amount of CSF.

Depending on your child’s symptoms, they may need tests to check how their immune system is working.

• Our Immunology Clinic’s large team of doctors has over 40 years of experience in diagnosing and treating children with conditions that affect their immune system.
• At our Immunology Diagnostic Laboratory we can do complex tests offered at only a few places in the world. Results from these tests help us know how to best treat your child's disease.
• Researchers at our Center for Immunity and Immunotherapies work to improve diagnosis and treatment of disorders that involve the immune system.

Some conditions affect a child’s nervous system. Your doctor may ask questions and do tests to check:

• Your child's ability to think and learn
• Their vision, hearing and other senses
• If muscles, balance, reflexes and coordination seem healthy

Pulmonary function tests (PFTs) measure how well your child breathes. Doctors use them to help diagnose and evaluate problems affecting your child’s lungs. Our Pulmonary Diagnostics Lab does many kinds of tests.

An electrocardiogram is a noninvasive test that records the electrical activity of the heart. This test is also called an ECG or EKG. It helps doctors check if the heart rate and rhythm are normal. This test also helps doctors see if your child has certain heart problems. Learn more.

Sometimes a child’s condition is caused by genetic changes (mutations) passed down from a parent (inherited). Some genetic changes do not cause a disease directly but they do make it more likely that a child will develop a disease.

Genetic testing can help confirm a diagnosis or rule out other problems. The test uses a sample of your child’s blood or cells from gently scraping the inside of their cheek. Doctors check for changes in genes that may show your child has an inherited disorder. Sometimes it helps to test family members to see if they carry a disease-causing gene. Highly experienced and certified geneticists interpret the results.

Seattle Children’s genetic counselors can advise you about the pros and cons of genetic testing. They explain test results and your chance of having another child with the condition in a future pregnancy. Counseling can help you make informed decisions about family planning and your child’s treatment.

Some parents learn their baby may have a condition even before birth. This can happen if:

• A routine ultrasound during pregnancy shows a problem
• A pregnant woman gets tested because other family members have a disease that can be passed on from parent to child

Our Fetal Care and Treatment Center can help your family and obstetrician get ready for your baby’s birth and plan treatment.