Spontaneous regression of a large lumbar disc extrusion

Abstract

Although the spontaneous disappearance or decrease in size of a herniated disc is well known, that of a large extruded disc has rarely been reported. This paper reports a case of a spontaneous regression of a large lumbar disc extrusion. The disc regressed spontaneously with clinical improvement and was documented on a follow up MRI study 6 months later. The literature is reviewed and the possible mechanisms of spontaneous disc regression are discussed.

Keywords: Lumbar disc extrusion; MRI; Spontaneous regression.

Fig. 1

Lumbar spine MRI 6 months earlier. A : Sagittal T2-weighted image of the initial magnetic resonance imaging study reveals a large herniated disc at the L4/5 level with caudal migration. B and C : Axial T2-weighted image of the initial MRI shows a left-side posterolateral extruded disc fragment and lateral stenosis at the L4/5 level.

Fig. 2

Lumbar spine MRI. A : Sagittal T2WI of the second round of MRI shows almost complete regression of the herniated nucleus pulposus at the L4/5 level. B and C : Axial T2WI of the second round MRI shows almost complete regression of the herniated nucleus pulposus and the remaining lateral stenosis at the L4/5 level without nerve root compression.