What is neuroblastoma?
Neuroblastoma is a cancer that originates in the tissues that form the sympathetic nervous system. The normal function of these nerves is to regulate the automatic and non-voluntary body functions such as heart rate, blood pressure, breathing, and digestion.
Neuroblastoma typically begins in the nerve tissues of the adrenal glands but may also begin in the nerves that are located anywhere along the spinal cord, including the neck, chest, or abdomen. The cancer can metastasize (spread) rapidly to other organs (ie, liver), lymph nodes, bones, and bone marrow.
This cancer is rare, affecting only about 1 in 100,000 people. It often develops at birth or soon after, and is most commonly diagnosed in children younger than 5 years of age.
What causes a neural tumor?
Its cause is unknown, but it is believed to form during normal development of the sympathetic nervous system. Gene abnormalities in persons with the tumor are typical. The gene associated with this tumor is named n-myc. This gene is normally functional for a brief period in the first trimester of fetal life and then is silenced throughout the rest of gestation as well as throughout life. If this gene is activated, the result can be development of a neuroblastoma.
What are the signs and symptoms of neuroblastoma?
The specific symptoms will depend on the site of the tumor. In many circumstances, the tumor will cause the child to have abdominal pain or non-specific tiredness. If the tumor has invaded the bone marrow, as it often does by the time it is diagnosed, the child may look pale due to anemia. A lump may be felt in the abdomen, neck, or chest. Common symptoms are dark circles around the eyes, an enlarged abdomen (particularly if the cancer has spread to the liver), difficulty breathing, bone pain or tenderness (if the cancer has spread to the bones), and weakness or loss of movement (paralysis) of the hips, legs, or feet.
Some less common signs are shortness of breath, severe diarrhea, uncontrolled eye movements, and uncoordinated movement. The syndrome of "dancing eyes – dancing feet" or opsoclonus-myoclonus, should quickly make the doctor think of neuroblastoma. Some children with neuroblastoma may also have problems with balance, also known as ataxia. Both opsoclonus-myoclonus and ataxia are known as a paraneoplastic syndrome and are associated with neuroblastoma.