Neuroblastoma is a type of childhood cancer that develops in immature nerve cells within the sympathetic nervous system. Part of the autonomic nervous system (which controls bodily functions we do not consciously control, such as breathing and heart rate), the sympathetic nervous system is made up of nerve fibers that run parallel to the spinal cord, ganglia (clusters of nerve cells) found along the nerve fibers, and nerve-like cells located in the adrenal glands. Neuroblastoma begins to grow in the very early forms of nerve cells as they develop in the embryo or fetus.
Neuroblastoma accounts for approximately 6% of all childhood cancers, with about 700 new cases of neuroblastoma diagnosed every year. It is the most common type of cancer in children under one year of age. The average age of diagnosis is between 1 and 2 years of age, while 90% of all cases of neuroblastoma are diagnosed by the age of 5. Neuroblastoma is rarely diagnosed in children over the age of 10.
About 33% of all neuroblastomas begin in the adrenal glands, while about 25% start in the sympathetic nerve ganglia located in or near the abdomen. Most other neuroblastomas begin in sympathetic ganglia located near the spine. The origin site of the neuroblastoma can lead to different types of symptoms; for instance, tumors within the ganglia are often felt as a bump or swelling in the abdomen or spine, while neuroblastoma in the adrenal glands can alter hormonal signals within the nervous system, leading to symptoms in other areas of the body unrelated to the cancer. In about 66% of cases, the neuroblastoma has spread to the lymph nodes and/or the bones at the time of diagnoses.
About Neuroblastoma: Detection and Diagnosis
Neuroblastoma is usually diagnosed after a parent or guardian notices one or more unusual symptoms in their child. The most common symptom of neuroblastoma is an unusual swelling in the abdomen, sometimes accompanied by a lack of appetite. The first step in diagnosis is a routine medical exam by a pediatrician; if neuroblastoma is suspected, your pediatrician will refer you to a pediatric oncologist (a specialist in childhood cancer), who will schedule a series of tests to determine whether your child’s symptoms are indeed caused by neuroblastoma.
The most common diagnostic tools for neuroblastoma include:
- Lab tests: Samples of your child’s urine and blood will be tested for markers of neuroblastoma. Because neuroblastoma alters the types of hormones the body creates, these hormones can be detected in the urine. A urine test can also help determine kidney function. Blood tests are used to check blood cell counts, kidney and liver function, and the salt balance in the body.
- Imaging tests: Imaging tests are used to help the oncologist look inside the body to determine if a tumor is present, how far the cancer has spread, and whether treatment has been effective. Imaging tests can include ultrasound, x-ray, CT scan, MRI scan, MIBG scan, and/or a PET scan. Unfortunately, some of these tests require children to stay very still for long periods of time, and/or require staying still in a small, confined space. Because most children with neuroblastoma are so young, these tests can be extremely difficult. Your oncologist may recommend sedation and/or a calming medication to make the tests easier for the child and to ensure more accurate results.
- Biopsies: Definitive diagnosis of neuroblastoma usually requires a biopsy, which involves removing some of the tumor and examining it under a microscope and/or conducting additional lab testing. Depending on the location of the tumor, the biopsy may be incisional (open) or needle (closed). An incisional biopsy involves removing a piece of the tumor through one or more incisions in the skin. During a needle biopsy, a thin, hollow needle is placed through the skin and into the tumor in order to pull out a sample of the tumor. For young children, biopsies are almost always conducted under general anesthesia.
These diagnostic tools will also be used to stage the neuroblastoma and determine its “risk groupings”. The staging and risk grouping, along with your child’s age and medical history, will help determine the appropriate course of treatment.
About American Childhood Cancer Organization
American Childhood Cancer Organization (ACCO) is a non-profit charity dedicated to helping kids with cancer and their families navigate the difficult journey from cancer diagnosis through survivorship. Internationally, ACCO is the sole U.S. member of Childhood Cancer International (CCI), the largest patient-support organization for childhood cancer in the world. Here in the United States, ACCO promotes the critical importance of ensuring continued funding into new and better treatment protocols for childhood cancer. And most importantly, ACCO is focused on the children: developing and providing educational tools for children fighting cancer and their families, empowering them in their understanding of childhood cancer and the medical decisions they must make during this difficult journey. All of ACCO’s resources are available free of charge for families coping with childhood cancer.