Devoted to diagnostic and interventional spine imaging and therapeutics


Imaging of a Dorsal Lumbar Lipomyelomeningocele With an Accessory Limb 2004

Symons, Sean, MPH, M.D.

We report the case of an infant born with a closed lumbar neural tube defect and an overlying skin covered dorsal mass. Plain radiography demonstrated bone within the mass. Computed tomography confirmed the presence of accessory bone and revealed spinal dysraphism with cord tethering. Sonography confirmed the spinal dysraphism and demonstrated a meningocele with possible myelocystocele. Magnetic resonance imaging demonstrated the myelomeningocele with cord tethering. There was syringohydromyelia above the defect and diastematomyelia below the defect. The mass was resected and the meningocele closed. Pathologically, the mass contained mostly mature fat with long bones, a scapula clavic le like structure, skeletal and smooth muscle, epidermal and endodermal derivatives, peripheral nerve, ganglion and astroglial tissue. Differential considerations included a parasitic twin or teratoma. However, the most appropriate diagnosis was that of spinal dysraphism with an accessory limb. There are eight other similar reported cases. The most plausible pathological explanation for these phenomena is secondary neural tube rupture with Swhwann cell implantation and dedifferentiation.