Neuroblastoma is a solid tumor or cancer. It occurs in the developing cells of the sympathetic nervous system, called neuroblasts. The sympathetic nervous system is responsible for involuntary actions of the body, such as blushing, increasing heart rate, and dilating the pupils of the eye. The majority of tumors (65%) are located above the kidney. However, tumors can begin anywhere in the body. Other common sites are the chest, neck or pelvis. The disease often spreads from its "primary" location to the bone marrow, bones or lymph nodes. In fact, in many cases the disease has already spread at the time of diagnosis.
There are approximately 650 new cases of neuroblastoma diagnosed in the US annually. Neuroblastoma is the most common solid tumor outside of the brain in children. Most children are diagnosed as toddlers, but neuroblastoma can present in infants and older teenagers as well.
What causes neuroblastoma?
Many researchers believe that neuroblastomas develop when normal neuroblasts (the immature cells of the sympathetic nervous system) fail to mature into nerve cells. Instead, they continue to grow and divide uncontrollably, leading to the growth of a mass of cancerous cells, or a tumor.
Researchers have started to identify mistakes, or "mutations", that occur in genetic material – the DNA – of neuroblastoma cells, but have yet to figure out exactly why those mutations happen in the first place. Many scientists believe that neuroblastoma and other childhood cancers are caused by a random mutation or mistake that happen during cell division.
What are the symptoms of neuroblastoma?
There are no symptoms of neuroblastoma that are common to all children with the disease. The symptoms are related to the location of the tumor. Common locations for neuroblastoma include the abdomen, the neck and chest. Some of the more common symptoms include:
- Abdominal selling, pain, constipation or difficulty urinating if tumor is present in the abdomen.
- Bone pain
- Fatigue, if the disease has spread to the bone marrow, causing a decrease in red blood cells (anemia).
- Bleeding and bruising, if the disease has spread to the bone marrow, causing a decrease in platelets.
- Drooping of the eyelid with a small pupul, and lack of sweating on the same side of the face.
Less frequent symptoms caused by hormones released by the neuroblastoma cells include:
- Fever
- Persistent diarrhea
- High blood pressure
- Rapid heartbeat
Pat Brophy, Children's Hospital of Philadelphia
July 2008