Myelocystocele is characterized by a large, ependyma-lined, cystic dilation of the caudal end of the central canal of the spinal cord; it projects dorsally through a lamina defect, with overlying varying amounts of lipomatous subcutaneous tissue. Myelocystoceles are associated with a tethered cord and meningocele, which communicates with the spinal subarachnoid space, but not with the central canal cyst.
Comment:
Localized dilatation of the central canal of the spinal cord which produces a fluid-filled sac or diverticulum which then protrudes through the cord and the defective dorsal dura between the posterior parts of the vertebra.