Spinal Lipoma in Children Homepage

Authors

Amparo Saenz, BM, FRCS

Dominic Thompson, FRCS (SN)

Section Editors

Bermans J. Iskandar, MD

Graham Fieggen, MD

Editor-in-Chief

Rick Abbott, MD

Introduction

Spinal lipomas are developmental abnormalities within the spectrum of closed spinal dysraphism, typically (but not exclusively) occurring in the terminal spinal cord. They are characterized by a midline adipose mass attached to the spinal cord through a defect in the bone and dura, which restricts the mobility of the terminal spinal cord. Chapman first classified lumbosacral lipomas into three subtypes in 1982: dorsal, transitional, and caudal/terminal (1). In 2010, Pang added a fourth category, the chaotic type (2). The initial presentation, surgical indications, technique, and outcome depend on the subtype and the symptomatology. While lipomas have been described at many sites within the neuroaxis, including wholly intramedullary spinal cord lipomas, this chapter refers to lipomas of the conus region.

Key Points

• Spinal lipoma origin unclear: The embryogenesis of conus region lipomas is not completely understood. Although there is not a direct relationship between folic acid and spinal lipomas, Sebold et al. (3) and Carter et al. (4) found that lipomyelomeningoceles may share at least some of the same genetic factors as open neural tube defects in some families. However, to determine whether there is a connection between folate supplementation and closed spinal defects will require large, well-designed prospective studies.
• Four subtypes: The classic description of spinal lipomas comprises four distinct subtypes: dorsal, transitional, caudal/terminal, and chaotic.
• Clinical presentation varies: Spinal lipomas can either be asymptomatic or exhibit symptoms such as pain, neurological deficits or orthopedic abnormalities (neuro-orthopedic syndrome), or neurogenic sphincter disturbance.
• Symptom causes differ: Spinal cord lipomas can cause symptoms owing to primary dysplasia or secondary to progressive traction on the terminal spinal cord and nerve roots (“tethered cord syndrome”).
• Operative timing and outcomes vary: The indications and timing of surgery remain controversial. Treatment of transitional and terminal lipomas generally yields better results when surgically addressed in asymptomatic children younger than 2 years. Dorsal lipomas tend to have a more favorable natural history. By contrast, chaotic lipomas typically have less favorable outcomes. Late deterioration due to retethering is a frequent occurrence after partial lipoma resection.
• Surgical treatment can be beneficial: Total or near-total resection of the lipoma, guided by intraoperative neurophysiological techniques, is associated with improved progression-free survival. Optimization of the cord-sac ratio by means of neurulation and expansion duraplasty appears to be a significant factor in improving progression-free survival.