Neuroblastoma is the most common extra-cranial solid tumor cancer in childhood and the most common cancer in infancy, with an annual incidence of about 650 new cases per year in the US. Close to 50 percent of neuroblastoma cases occur in children younger than two years old. It is a neuroendocrine tumor, arising from any neural crest element of the sympathetic nervous system, a nerve network throughout the body that carries messages from the brain.

Neuroblastoma often begins in the nerve tissue of the adrenal glands, but can also develop in nerve tissues in the neck, chest, abdomen, or pelvis.  Neuroblastoma may also begin in nerve tissue near the spine in the neck or in the spinal cord.  There are two adrenal glands, one on top of each kidney in the back of the upper abdomen.  The adrenal glands produce important hormones that help control heart rate, blood pressure, blood sugar, and the way the body reacts to stress. 

Neuroblastoma most often begins during early childhood, usually in children younger than 5 years. It sometimes forms before birth but is usually found later, when the tumor begins to grow and cause symptoms. In rare cases, neuroblastoma may be found before birth by fetal ultrasound.

By the time neuroblastoma is diagnosed, the cancer has usually metastasized (spread), most often to the lymph nodes, bones, bone marrow, liver, and skin.

Neuroblastoma is both the best and the worst of childhood cancers.  Unlike other cancers some forms of the disease are known to spontaneously regress on its very own withouth treatment while other forms of the disease are extrememly difficult to cure even with the most intensive multimodal therapies available.

Neuroblastoma is stratified into three risk categories: low, intermediate, and high risk.  Each risk groups has very different treament regimens and survival statistics.