Spontaneous regression of congenital spinal lipomas of the conus medullaris. Report of two cases.

Spinal lipomas of the conus (SLCs) are relatively common closed neural tube defects. Many of these lesions are treated surgically at the time of diagnosis and, therefore, little has been documented about their true natural progression. In addition, the changes, if any, of SLCs in pediatric patients have not been widely studied or documented using magnetic resonance (MR) imaging. In this report, the authors describe two asymptomatic infants in whom serial MR imaging revealed substantial spontaneous regression of SLCs, a phenomenon that has been very rarely reported in the literature. These are the first MR imaging-documented cases of near-complete spontaneous regression of SLCs in infants.