Neuroblastoma is a malignant tumor of the autonomic nervous system. It is a neuroendocrine tumor, arising from any neural crest element of the sympathetic nervous system. Neuroblastoma is a disease of early childhood with approximately 90% of patients presenting before 5-years of age and almost 50% within the first 2-years of life. In childhood, about 40% of neuroblastomas arise in the adrenal medullae. The remainder occurs anywhere along the sympathetic chain, with the most common locations being the paravertebral region of the abdomen (25%) and posterior mediastinum (15%). Tumors may arise in numerous other sites, including the pelvis and neck and within the brain (cerebral neuroblastomas). It is the second most common solid malignancy of childhood. In young children, under age 2 years, neuroblastomas generally present with large abdominal masses, fever, and possibly weight loss. In older children, they may not come to attention until metastases produce manifestations, such as hone pain, respiratory symptoms, or gastrointestinal complaints. Neuroblastomas may metastasize widely (Present in 60-70%- O.P. Ghai 7th/5990) through the hematogenous and lymphatic systems, particularly to liver, lungs, and bones, in addition to the bone marrow. Proptosis and ecchymosis may also be present because the periorbital region is a common metastatic site. Bladder and bowel dysfunction may be caused by paraspinal neuroblastomas that impinge on nerves. In neonates, disseminated neuroblastomas may present with multiple cutaneous metastases with deep blue discolora­tion to the skin (earning the rather unfortunate designation of "blueberry muffin baby)" About 90% of neuroblastomas, regardless of location, produce catecholamines (similar to the catecholamines associ­ated with pheochromocytomas), which are an important diagnostic feature (i.e., elevated blood levels of catecholamines and elevated urine levels of metabolites, vanillylmandelic acid (VMA), and homovanillic acid (HVA) Children older than age 5 years usually have extremely poor outcomes irrespective of the stage (Robbins 7th/500-503) NB can present as a paraneoplastic syndrome of autoimmune origin manifesting as ataxia or opsomyoclonus ("dancing eye & dancing feet").