It is a cancer that arises from immature nerve cells called neuroblasts. Neuroblastoma most often begins in the adrenal glands, which are located on top of the kidneys. However, tumors can form anywhere along the sympathetic nervous system, including the chest, neck, abdomen, or pelvis. In some children, the cancer is localized at diagnosis. In others, neuroblastoma has already spread to the lymph nodes, bone marrow, bones or liver.