Our Approach to Diagnosis

We are very experienced diagnosing all types of cancers and blood disorders, including very rare cancers and inherited syndromes. An accurate diagnosis is the key to planning the right treatment for your child.

Our whole focus is newborns, children and young adults (up to age 30 for some cancers). Seattle Children’s doctors are board certified in pediatrics, with extra training and years of experience caring for kids. They also have board certification in blood disorders and cancer (hematology-oncology). You can be sure our team has the skills and experience to find the cause of your child’s illness.

In some cases, diagnosis and treatment planning include studying your child’s genetic makeup to understand their disease, whether it’s a tumor or inherited blood disorder. We also sometimes study the genetic changes in your child’s tumor to understand what went wrong in the tumor cells to turn them into cancer. Studying your child’s genetics and the genetics of the cancer help us give your child the most effective treatment for their specific disease.

Need a diagnosis?

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Need a second opinion?

If you need a second opinion, please contact us. Many of the children we treat received care previously at another hospital.

We will work with you to understand what you are looking for in the visit. Afterward, we will partner with you to determine next steps.

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Diagnostic Tools and Services

We only do tests that are medically needed. These tools, lab tests and services help us make a diagnosis for your child, plan the best treatment and work with you to make the right choices for your family.

  • Testing a sample of your child’s blood helps diagnose many types of blood disorders and cancers. Your doctor may order these tests, depending on your child’s symptoms:

    • Complete blood count (CBC) – Tells how many cells of each type are moving through the bloodstream and what they look like
    • Blood chemistry – Finds chemicals in the blood that may be signs of disease and tell the health of different organs of the body

    Your doctor may measure the levels of certain substances in your child’s blood, other body fluids or tissue, such as:

    • Tumor markers (substances that are found in higher levels in people with cancer)
    • Clotting factors (proteins that help blood clot)
    • Hormones
    • Hemoglobin (HGB, the part of red blood cells that carry oxygen)

  • We may take pictures 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
    • MIBG (metaiodobenzylguanidine) scan
    • Ultrasound

    As we treat your child, we may do imaging studies to check the effects of treatment. Doctors at Seattle Children’s were pioneers in using MRI and PET scans to check that chemotherapy has shrunk a child’s tumors before surgery. This helps ensure the best timing for surgery.

  • Doctors may test your child’s blood, bone marrow or other body tissue to look for changes in the chromosomes of cancer cells. These tests help tell the specific type of cancer and guide doctors in choosing the best treatment for your child. This is called cytogenic testing.

    Through our precision medicine program, we develop new clinical lab tests such as gene sequencing. 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.

    Sometimes a specialist sees chromosomal changes by looking at the cells under a microscope. Seattle Children’s Genetics Lab also does more specialized tests, including fluorescence in situ hybridization (FISH). This test helps in diagnosing some cancers and deciding if certain targeted drugs might help. A board-certified cytogeneticist reviews and interprets the results.

  • If doctors suspect cancer, they may remove a small piece of a tumor, lymph node or other body tissue. Often, doctors use a needle to remove the sample. For hard-to-reach tissue, surgery may be needed. Sometimes an entire lymph node or tumor is removed during biopsy.

    A doctor with special training in diagnosing disease based on lab tests (pathologist) looks at the tissue under a microscope. The pathologist often does tests to help tell the type of cells and to make a diagnosis.

  • Sometimes doctors use antibodies to help tell the specific type of cancer your child has. An antibody is an immune protein that will attach only to certain proteins (antigens) on a cell. Some antibodies only attach to 1 type of cancer. Other antibodies may react to a few types of cancer. A stain is added to the antibody to make the cell easier to see. This type of test is called immunohistochemistry.

    Special antibodies are added to a blood or biopsy sample in a test called flow cytometry. Each antibody only sticks to cells with a matching antigen. As the cells flow past a laser light, the cells that contain the antibodies give off light. A computer measures and analyzes the light. If most of the antigens are of the same type, it’s more likely to be cancer that started from a single abnormal cell.

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

    • Tell if cancer has spread to the soft inner part of bone (bone marrow)
    • See how well your child’s 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
    • Push a larger needle into the bone to remove a small amount of bone marrow
    • Look at the samples under a microscope

  • 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.

    Young children get medicine to make them sleep and stay still during the procedure. In older children, a small area of your child’s lower back is made numb. 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 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 or their ability to think or learn. Your doctor may ask questions and do further tests to check:

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

  • Sometimes a child’s condition is caused by genetic changes (mutations) passed down from a parent. Some genetic changes don’t 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 conditions. 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 point to an inherited disorder. Sometimes it is helpful for family members to get tested 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 Prenatal Diagnosis and Treatment Program can help your family and obstetrician get ready for your baby’s birth and plan treatment.

Contact Us

Contact the Cancer and Blood Disorders Center at 206-987-2106 for an appointment, a second opinion or more information. We welcome calls from families, whether you live near Seattle or far away.

To make an appointment, you can call us directly or get a referral from your child’s primary care provider. We encourage you to coordinate with your pediatrician or family doctor when coming to Seattle Children’s.

Providers, see how to refer a patient.