Two Cases of Large Filar Cyst Associated with Terminal Lipoma: Relationship with Retained Medullary Cord

A small, incidental filar cyst associated with terminal lipoma is thought to be caused by failure of secondary neurulation; however, the precise embryologic background is not fully understood. Retained medullary cord (RMC) also originates from late arrest of secondary neurulation. The central feature of RMC histopathology is a central canal-like ependyma-lined lumen with surrounding neuroglial core. We surgically treated 2 patients with a large...