Spinal meningeal cyst.

: A case of meningeal cyst of the spine in the thoraco-lumbar region is described. Although water-soluble myelography may disclose a filling defect and possibly reveal communication between the cyst and the subarachnoid space, computerized tomographic myelography more readily reveals communication between the cyst and the subarachnoid space. This finding allows accurate diagnosis of a spinal meningeal cyst and rules out other mass lesions. A classification comprising three categories is made: spinal extradural meningeal cysts without spinal nerve root fibers (Type I), spinal extradural meningeal cysts with spinal nerve root fibers (Type II) and spinal intradural meningeal cysts (Type III). Final characterization is based on operative inspection and histological examination.