Appearance and vanishing of a spinal intradural arachnoid cyst after multiple epidural corticosteroid injections. A spontaneously resolving cause of symptomatic lumbar stenosis.

BACKGROUND

Spinal intradural arachnoid cyst is a rare lesion, sometimes acquired.

PURPOSE: To describe the appearance and later spontaneous disappearence of a lumbar intradural arachnoid cyst, following perineural corticoid injections.

METHOD: Review of the clinical data and imaging, with final spontaneous return to initial state.

DISCUSSION: Atypical intradural arachnoid cysts can be related to perineural injections and can cause symptoms of spinal stenosis. Its spontaneous vanishing is a very rare event, up to now unreported.