Morota Classification Scheme of Spinal Lipoma in Children

Spinal Lipoma Types

Rather than categorize spinal lipomas according to their surgical anatomy, in 2018, Morota et al. classified them according to the embryological phase of neurulation in which failure occurs that results in the development of spinal lipomas in children (7).

• Type 1 – Failure in primary neurulation: Type 1 lipomas involve a failure in primary neurulation in which the lipoma-cord interface occurs on the dorsal surface of the spinal cord, while the conus is intact.
• Type 2 – Failure in primary/secondary junctional neurulation: Type 2 lipomas involve a failure in the primary/secondary junctional neurulation in which the lipoma is attached to the spinal cord, but the conus medullaris is malformed and difficult to recognize.
• Type 3 – Failure of early-phase secondary neurulation: Type 3 involves early-phase secondary neurulation failure in which the lipoma extends in the caudal direction, penetrating the caudal end of the dura to connect with subcutaneous fat through the enlarged sacral hiatus. There is no pathological vertebral defect or fascial defect due to the lipoma.
• Type 4 – Failure of late-phase secondary neurulation: Type 4 lipomas involve late-phase secondary neurulation failure in which the spinal lipoma is in the filum terminale.