Evaluation and Treatment of Lumbar Spine Extradural Cysts: A Narrative Review

The main objective was to describe the different types and characteristics of lumbar spine extradural cysts and their optimal treatment options with a focus on endoscopic technique. We searched Pubmed, EMBASE, Medline, and Google Scholar for articles published between 1967 and 2020 using the keywords "Spinal Cyst," "Extradural Cyst," and "Lumbar Cyst." The various anatomical and histological types of the extradural cysts with their presentations, etiologies, imaging, and optimal treatment with a focus on endoscopic techniques were reviewed from the articles. Lumbar spinal cysts are relatively rare pathologies that might cause radicular symptoms similar to lumbar disc herniation. Spinal extradural cysts are classified either histologically based on the cyst lining tissues (synovial cysts or non-synovial, ganglion cysts) or anatomically based on the structure of origin (epidural cysts, ligamentum flavum cysts, discal cysts, post-discectomy pseudocysts, posterior longitudinal ligament cysts, facet cysts). Surgical excision is the recommended treatment of symptomatic cysts with endoscopic techniques being a viable option. Extradural lumbar cysts can be identified based on their histological structure or depending on their structure of origin. Regardless of their classification, they could all give similar clinical findings, and the optimal treatment would be surgical excision with endoscopic technique being a viable option with a satisfactory outcome.