Spinal arachnoid cysts are benign, space-occupying lesions that are filled with clear CSF-like fluid and are usually found in the intracranial compartment. Less frequently they are seen in the spine, as in this case. Spinal arachnoid cysts can be classified into Intradural and extradural arachnoid cysts.

(Authors Dr. Aruna Pallewatte, Dr Lasitha Wickremaratne)