Health A-Z

Medical Content Created by the Faculty of the
Harvard Medical School

Neuroblastoma

What Is It?

Neuroblastoma is the most common childhood cancer to develop outside the brain. It accounts for about 8% of childhood cancers. The average age at diagnosis is 2 years old. However, there is a specific subclass of neuroblastoma called Stage 4S, that occurs in infants younger than 1 year. Despite the presence of metastatic (disseminated) disease, these patients tend to do extremely well, and there have been instances of spontaneous regression of these neuroblastomas in these infants.

Neuroblastomas form in the nerve cells responsible for the body's "fight-or-flight" response, which is the ability to react to a life-threatening emergency. These nerve cells form the sympathetic nervous system.

Neuroblastomas usually form in one of two parts of the sympathetic nervous system:

• The adrenal glands. These glands in the abdomen produce the hormone adrenaline, also known as epinephrine, which is released in an emergency to help the body react. When a neuroblastoma develops in the adrenal gland, it typically grows into a large, firm abdominal mass that can compress nearby organs.

• The chain of sympathetic ganglia. These are collections of nerves near the backbone (spine). When a neuroblastoma develops along the sympathetic chain, it can invade nearby areas of the spine and cause injury to spinal nerves.

Neuroblastomas can develop in other areas of the body, including the chest, neck and pelvis, but this is less common.

As a neuroblastoma grows, it has the potential to spread (metastasize) to other areas, most commonly to the bone marrow, bones, liver and skin.

There is no conclusive evidence that neuroblastoma is related to any toxic chemical or environmental risk factor. Genetic (inherited) factors seem to influence the development of some neuroblastomas.