Intraspinal extradural cysts communicating with adjacent herniated disks: imaging characteristics and possible pathogenesis.

Abstract

We report two cases of intraspinal extradural cysts communicating with an adjacent herniated disk that we term "disk cysts." These cysts were well defined and homogeneous, and were present in the ventrolateral extradural space adjacent to a lumbar herniated disk. They had rim enhancement on contrast-enhanced MR images, and communication with a herniated disk was revealed by diskography.