Perineural cyst

This code represents a fluid-filled sac that forms along the nerve root sheath, typically in the sacral region of the spine. These cysts, also known as Tarlov cysts, are often asymptomatic but can cause neurological symptoms if they enlarge and compress surrounding nerves.

Use this code when documentation explicitly identifies a perineural cyst, particularly when it is an incidental finding or the primary diagnosis for a patient presenting with symptoms attributable to the cyst. Supporting documentation should include imaging reports (e.g., MRI, CT) confirming the presence and location of the cyst.

• Differentiate from other spinal cysts (e.g., arachnoid cysts, synovial cysts) which have distinct codes.
• Code any associated neurological symptoms separately, linking them to the cyst if causality is documented.
• Ensure the documentation specifies "perineural" or "Tarlov" cyst to support this specific diagnosis.