Neuroblastoma is a cancer that develops from nerve cells found in several areas of the body. Neuroblastoma most commonly arises in and around the adrenal glands, which have similar origins to nerve cells and sit atop the kidneys. However, neuroblastoma can also develop in other areas of the abdomen and in the chest, neck and pelvis, where groups of nerve cells exist. Neuroblastoma most commonly affects children age 5 or younger, though it may rarely occur in older children and adults. Neuroblastoma is the most common cancer in babies and often has a very good prognosis in children younger than 1.
Neuroblastoma begins in neuroblasts — immature nerve cells that a fetus makes as part of its development process. As the fetus matures, neuroblasts eventually turn into nerve cells and fibers and the cells that make up the adrenal glands. The majority of neuroblasts mature by birth, though studies have found a small number of immature neuroblasts in newborns. In most cases, these neuroblasts will mature or disappear. Others, however, form a tumor — a neuroblastoma. However, because neuroblastoma usually affects very young children, researchers believe the mutation occurs during pregnancy, or possibly even before conception.
The only factor known to increase the risk of neuroblastoma is a family history of the cancer. Yet, familial neuroblastoma is thought to comprise a very small number of neuroblastoma cases. In most cases of neuroblastoma, a cause is never identified.
Signs and symptoms of neuroblastoma vary depending on what part of the body is affected.
Neuroblastoma in the abdomen — the most common form — may cause signs and symptoms such as:
- Abdominal pain
- A feeling of fullness in the abdomen
- A mass under the skin that isn’t tender when touched
- Changes in bowel habits, such as constipation
- Changes in urinary habits, such as having to go to the bathroom more often
- Swelling in the legs
Neuroblastoma in the chest may cause signs and symptoms such as:
- Swelling in the face
- Changes to the eyes, including drooping eyelids and unequal pupil size
Other signs and symptoms that may indicate neuroblastoma include:
- Lumps of tissue under the skin
- Eyeballs that seem to protrude from the sockets (proptosis)
- Dark circles, similar to bruises, around the eyes
- Back pain
- Curvature of the spine (scoliosis)
- Unexplained weight loss
- Bone pain
Complications of neuroblastoma may include:
Spread of the cancer (metastasis). Neuroblastoma may spread (metastasize) to other parts of the body, such as the lymph nodes, bone marrow, eyes, liver, skin and the tissue that surrounds the spinal cord (dura).
Spinal cord compression. Tumors may grow and press on the spinal cord, causing spinal cord compression. Spinal cord compression may cause pain and paralysis.
Signs and symptoms caused by tumor secretions. Neuroblastomas may secrete certain chemicals that irritate other normal tissues, causing signs and symptoms called paraneoplastic syndromes. One paraneoplastic syndrome that occurs rarely in people with neuroblastoma causes rapid eye movements and difficulty with coordination. Another rare syndrome causes abdominal swelling and diarrhea.
Tests and procedures used to diagnose neuroblastoma include:
Physical exam. Your child’s doctor conducts a physical exam to check out any signs and symptoms. The doctor will ask you questions about your child’s habits and behaviors.
Urine and blood tests in children. These may indicate the cause of any signs and symptoms your child is experiencing. Urine tests may be used to check for high levels of certain chemicals that result from the neuroblastoma cells producing excess catecholamines.
Imaging tests. Imaging tests may reveal a mass that may indicate a tumor. Imaging tests may include X-ray, ultrasound, computerized tomography (CT) scan and magnetic resonance imaging (MRI), among others.
Tumor biopsy. If a mass is found, your child’s doctor may want to remove a sample of the tissue for laboratory testing (biopsy). An incisional biopsy is a surgical procedure to remove a small piece of tissue from the tumor. If the cancer is small and confined to one area, the surgeon may remove the entire tumor and send it to a laboratory for examination (excisional biopsy). Specialized tests can reveal what types of cells are involved in the tumor and specific genetic characteristics of the cancer cells. This information helps your child’s doctor devise an individualized treatment plan.
Bone marrow biopsy. Your child may also undergo bone marrow biopsy and bone marrow aspiration procedures to see if neuroblastoma has spread to the bone marrow — the spongy material inside the largest bones where blood cells are formed. In order to remove bone marrow for testing, the surgeon inserts a needle into your child’s hipbones or lower back and draws out the marrow.
In rare cases, neuroblastoma may be detected during fetal ultrasound before a baby is born. Analysis of the mother’s urine can give other clues that may lead doctors to suspect neuroblastoma.
What treatment or combination of treatments your child receives for neuroblastoma depends on the risk category.
Surgeons use scalpels and other surgical tools to remove cancer cells. In children with low-risk neuroblastoma, surgery to remove the tumor may be the only treatment needed. Whether the tumor can be completely removed depends on its location and its size. Tumors that are attached to nearby vital organs — such as the lungs or the spinal cord — may be too risky to remove. In intermediate-risk and high-risk neuroblastoma, surgeons may try to remove as much of the tumor as possible. Other treatments, such as chemotherapy and radiation, may then be used to kill remaining cancer cells.
Chemotherapy uses chemicals to destroy cancer cells. Chemotherapy targets rapidly growing cells in the body, including cancer cells. Unfortunately, chemotherapy also damages healthy cells that grow quickly, such as cells in the hair follicles and in the gastrointestinal system, which can cause side effects. Children with low-risk neuroblastoma that can’t be removed surgically may receive low doses of chemotherapy. Sometimes chemotherapy is administered before surgery (neoadjuvant chemotherapy) to shrink the tumor to a size that’s more easily removed. In other cases, chemotherapy may be the only treatment. Children with intermediate-risk neuroblastoma often receive a combination of moderate-intensity chemotherapy drugs. Chemotherapy is often given before surgery to improve the chances that the entire tumor can be removed.
Children with high-risk neuroblastoma usually receive high doses of chemotherapy drugs to shrink the tumor and to kill any cancer cells that have spread elsewhere in the body.
Radiation therapy uses high doses of energy particles to destroy cancer cells. Radiation therapy primarily affects the area where it’s aimed. Your child’s radiation therapy team tries to protect the healthy cells near the cancer, but some healthy cells may be damaged by the radiation. What side effects your child experiences depends on where the radiation is directed.
Children with low-risk or intermediate-risk neuroblastoma may receive radiation therapy if surgery and chemotherapy haven’t been helpful.
Stem cell transplant
Children with high-risk neuroblastoma may receive a transplant using their own blood stem cells (autologous stem cell transplant). The bone marrow makes stem cells, which mature and develop into the red and white cells and platelets that make up the blood. Your child undergoes a procedure that filters and collects stem cells from his or her blood. Then high doses of chemotherapy are used to kill any remaining cancer cells in your child’s body. Your child’s stem cells are then injected into your child’s body, where they can form new, healthy blood cells.
Long-term and late side effects of cancer treatment
Small children can’t understand what’s happening to them as they undergo cancer treatment. To help your child cope, try to maintain your normal routine as much as possible. Try to arrange appointments so that your child can have a set nap time each day. Have routine mealtimes. Allow time for play when your child feels up to it. If your child must spend time in the hospital, bring items from home that help him or her feel more comfortable.