RESUMEN
Ganglioneuroblastoma is a rare tumor originating from the sympathetic chain. It is intermediate between the highly malignant neuroblastoma and the benign ganglioneuroma. The predilection sites of ganglioneuroblastoma are the retroperitoneum and mediastinum but involvement of the structures around the spinal cord is infrequent. A 4 year-old girl who had progressive weakness in both lower extremities had a tiptoe gait for 2 months. A magnetic resonance imaging (MRI) study revealed a heterogeneous enhancing mass in the right mediastinum and paraspinal areas. A biopsy of the mass confirmed a ganglioneuroblastoma with many neuroblasts and nodules of ganglion cells. This is an unusual case of a child with spastic paraplegia caused by ganglioneuroblastoma of the thoracic cavity.