Hypertrophic retromedullary venous drainage in spinal cord tumours: MR visualisation.

Pseudoangiomatous dilatation of retromedullary veins at myelography was noted in three cases of intramedullary spinal cord tumours. This concerned two haemangioblastomas at levels Th8 and L1, respectively, and an ependymoma of the conus terminalis. MRI accurately demonstrated the tumoural mass, together with the enlarged and tortuous draining perimedullary veins. In patients with dilated vascular shadows on myelography, MRI should be performed before medullary angiography to differentiate between spinal vascular malformations and intramedullary tumours with enlarged draining veins.