Neuroblastomas are unusual cancers of immature or developing nerve cells in infants or young children. They often metastasize (spread) to other parts of the body.

What Are Neuroblastomas?

Neuroblastomas are malignant * tumors * of the autonomic nervous system * . They occur when primitive neurons (nerve cells) fail to mature normally and begin to divide uncontrollably. Neuroblastomas may release hormones * that cause changes in the body. They can also affect some brain functions.

About one-third of all neuroblastomas are diagnosed during the first year of life, and 79 percent are diagnosed by the age of four. Only about 2 percent of neuroblastomas occur in children over 10 years of age or in adults. These tumors are slightly more common in boys than in girls.

About one-half of neuroblastomas begin in the nerve-like cells in the medulla at the center of the adrenal glands.

About one-half of neuroblastomas begin in the nerve-like cells in the medulla at the center of the adrenal glands.
Biophoto Associates/Science Source.

Two-thirds of neuroblastomas originate in the abdomen (commonly called the belly). About one-half of these begin in the nerve-like cells in the medulla at the center of the adrenal glands * , and one-half originate in clusters of nerves called ganglia in the abdomen. Other neuroblastomas may come from the chest or neck ganglia.

Sometimes, especially in very young infants, neuroblastoma cells die on their own and the tumor disappears. At other times, the neuroblastoma cells spontaneously mature into ganglion cells that do not continue to divide and the tumor becomes a benign ganglioneuroma, which means the tumor is not serious or cancerous. A ganglioneuroblastoma is a tumor that contains both malignant and nonmalignant cells.

What Causes Neuroblastomas?

The causes of neuroblastomas were not well understood as of 2016. Nerve and adrenal medulla cells develop from fetal * cells called neuroblasts. Neuroblastomas are believed to occur when neuroblasts fail to mature due to mutations in their DNA * . Instead, the neuroblasts continue to grow and divide.

About 1 to 2 percent of neuroblastomas appear to have a hereditary component, with other family members having had the cancer as infants. Children with this familial form tend to be diagnosed at a younger age, and they often develop neuroblastomas in two or more organs.

How Common Are Neuroblastomas?

Neuroblastomas are the most common cancer in infants and the fourth most common cancer in children. There are about 700 new cases in the United States every year.

What Are the Symptoms of Neuroblastomas?

The symptoms of neuroblastomas depend on the original location of the tumor and how far the cancer has metastasized (spread). The most common sign is a lump or mass, usually in the abdomen. The abdomen may swell, and the child may complain of a stomachache. Masses can be found elsewhere in the body, such as the neck or back of the eye. Depending on the location of the neuroblastoma, symptoms may include constipation or breathing difficulty, vision changes, or behavioral problems. Neuroblastomas frequently spread to the bones, and older children may complain of bone pain or have difficulty walking.

Paraneoplastic (caused by cancer located elsewhere in the body) syndromes are associated with less common symptoms caused by hormonereleasing neuroblastomas:

Opsoclonus-myoclonus-ataxia syndrome, also known as “dancing eyes, dancing feet,” is an uncommon symptom characterized by irregular rapid eye movements, muscle spasms, difficulty walking, and possibly difficulty in speaking. Surprisingly, neuroblastomas that cause this syndrome are less life-threatening than other forms.

How Are Neuroblastomas Diagnosed and Treated?


Because of their early age of onset, neuroblastomas can be difficult to diagnose. Up to 60 percent of cases are not diagnosed until they have already metastasized, especially to the lymph nodes * , bones, bone marrow * , liver, or skin. Rarely, neuroblastomas are diagnosed during a prenatal * ultrasound * . Sometimes neuroblastomas are discovered during tests for other childhood diseases. These cases usually have good outcomes and may not even require treatment.

About 90 percent of neuroblastomas overproduce chemicals called catecholamines * that can be detected in the blood or urine. Elevated levels of the chemical messengers dopamine * or norepinephrine * in the blood can be a sign of neuroblastoma. Additional tests measure blood cell counts, liver and kidney function, and salt balance.


The International Neuroblastoma Staging System may be used to measure the extent of the cancer, which helps determine the treatment and prognosis:

Imaging tests used to diagnose and stage neuroblastomas include:

A definitive diagnosis of neuroblastoma requires a biopsy * . The biopsied tissue may be tested with antibodies * against neuroblastoma cells.

About one-half of neuroblastomas spread to the bone marrow. Bone marrow is sampled by aspiration * and biopsy to diagnose and stage the cancer.


Treatment for neuroblastoma usually includes one or more of the following: