Congenital vascular malformation of spinal cord simulating diastematomyelia.

Diastematomyelia is usually caused by a midline bony, cartilaginous or fibrous spur. A case is presented with splitting of the spinal cord by a large arteriovenous malformation at the thoracolumbar junction. A hairy skin patch, kyphoscoliosis, vertebral anomalies and an arachnoidal cyst were found adjacent to the vascular and neural malformations.