Intraspinous postlaminectomy pseudomeningocele.

Pseudomeningoceles are uncommon complications of lumbar surgery. They are encapsulated cerebrospinal fluid collections developing extradurally as a consequence of incidental dural tears. They are typically located in the paraspinal compartment and occasionally reach the subcutaneous space. We describe the case of a patient in whom a postlaminectomy pseudomeningocele developed over a 10-year period within the L5 spinous process and remained completely encircled within its bony boundaries. The surgical implications of this finding are discussed.