Lipomyelocele is one of the most common closed spinal dysraphism. It is seen in thoracolumbar region and usually presents as a fatty subcutaneous mass.
It is twice as common as lipomyelomeningocele.
Affected individuals are usually asymptomatic at birth, but many (~ 50%) show presence of high-risk cutaneous markers as listed below:
- atypical dimples
- acrochordons (pseudo-tails)
- aplasia cutis
- dermoid cyst or sinus
As the spinal canal grows, there is a distortion of nerve roots with growth thereby leading to neurological deficits, highlighting the importance of early diagnosis.
There is a premature separation of surface ectoderm before formation of proper neural tube with the ingress of mesoderm (which forms fatty elements). The mesoderm prevents proper neurulation.
Posterior spinal defect noted which is covered with skin and shows interspersed lipomatous tissue. The neural placode-lipoma interface lies within the spinal canal or at its edge with normal anterior subarachnoid space.
There is usually associated tethered low-lying cord or syrinx of terminal spinal cord.
Clinical differential diagnosis
Closed spinal dysraphism of thoracolumbar region presenting as subcutaneous mass may be due to:
Imaging differential diagnosis
- lipomeningomyelocele: the lipoma-placode interface lies outside the spinal canal with resultant enlargement of anterior subarachnoid space
- 1. Naidich TP, McLone DG, Mutluer S. A new understanding of dorsal dysraphism with lipoma (lipomyeloschisis): radiologic evaluation and surgical correction. AJR Am J Roentgenol. 1983;140 (6): 1065-78. doi:10.2214/ajr.140.6.1065 - Pubmed citation
- 2. French BN. The embryology of spinal dysraphism. Clin Neurosurg. 1984;30: 295-340. Pubmed citation