Lipomyelocele

Lipomyelocele

MR – Sagittal T1 and axial T2 images of the lumbosacral spine demonstrate 1) dermal sinus tract extending into the spinal canal, 2) large infiltrative intraspinal lipoma dorsal to a dysplastic neural placode, 3) tethered neural placode at the lumbosacral junction and 4) lumbosacral dysrhaphism.

Lipomyeloceles are a skin covered dysraphic congenital abnormality of the spine. Lipomas extend from the subcutaneous soft tissues into the spinal canal through a dysraphic defect and are adherent to the dorsal aspect of the spinal cord/neural placode. Patients may present with a soft subcutaneous lumbosacral mass, bladder or bowel dysfunction, lower extremity weakness and/or lower extremity orthopedic anomalies.

Tethering is invariably present. The thecal sac is focally enlarged at the level of dysraphism. The subarachnoid space anterior to the spinal cord/placode is normal. The dorsal surface of the placode has no ependymal lining and is immediately adjacent to the lipoma. The extent of the lipoma is not confined to the levels of dysraphism.

Associated abnormalities are common and include segmentation and reduction defects of the spine(butterfly vertebrae and caudal regression), gastrointestional anomalies (imperforate anus, anal stenosis, and anal malposition), and genitourinary malformations.

Barkovich AJ. Pediatric Neuroimaging, 4th Ed. Lippincott, Williams and Wilkins (2005).