Neuroblastoma

Epidemiology

Neuroblastoma is the most common solid tumor of infancy and childhood, outside the central nervous system. Children < 5 years of age are most commonly affected. It usually arises from the adrenal medulla (40%), but tends to involve the spine and paraspinal regions in 25% of cases. Paraspinal involvement occurs most frequently in the thoracic and lumbar regions and is rare in the cervical area. Only 2 to 4% of lesions arise primarily in the neck. There is a slight male predilection. Ganglioneuroma and ganglioneuroblastoma present later than neuroblastomas and are most often seen in the 5- to 8-year age group

Clinical Features

For neuroblastomas that involve the extracranial head and neck, the common presentation is a palpable mass that may be mildly painful. The most common presenting symptoms for paraspinal masses that extend into the spinal canal include local pain and spinal cord dysfunction.

Pathology

Neuroblastoma arises from primitive cells called neuroblasts, which are of neural crest origin. These neural crest cells embryologically form the adrenal medulla and the paravertebral sympathetic chain. The tumor is frequently hemorrhagic. Histologically, neuroblastomas are composed of small primitive round cells with hyperchromatic dense nuclei. Calcifications are seen in 10% of cases.