Lumbar discal cyst causing bilateral radiculopathy

Abstract

Background: Discal cyst is a rare lesion that can result in clinical symptoms typical of disc herniation manifesting as a unilateral single nerve root lesion. To the best of the authors' knowledge, this is the first reported case of discal cyst resulting in bilateral radiculopathy.

Case description: A 48-year-old female presented with bilateral sciatica and neurogenic claudication for 3 months. Magnetic resonance imaging revealed an extradural cystic lesion compressing the ventral aspect of the thecal sac at the level of the L3-L4 intervertebral disc. The lesion showed low and high signal intensities on T1- and T2-weighted images, respectively. Total excision of the cyst was achieved after a left hemipartial laminectomy of L3, and an obvious communication with the disc space was found. Bilateral sciatica was immediately resolved after surgery, and was sustained at the two-year follow-up. The histological diagnosis was consistent with a discal cyst.

Conclusions: Although a discal cyst is extremely rare, the possibility of a discal cyst should be considered in differential diagnosis of patients with radiculopathy, particularly when encountering any extradural mass lesion ventral to the thecal sac. Surgical resection is the most employed therapeutic method for symptomatic lumbar discal cysts.

Keywords: Bilateral; discal cyst; lumbar spinal stenosis; radiculopathy.

Figure 1

Sagittal (a) and axial (b) T2-weighted MRI demonstrating a cystic lesion at the level of L3-4 intervertebral disc. In sagittal (c) T1-weighted MRI, rim enhancement of the lesion was appreciated after gadolinium administration

Figure 2

Histopathological examination of the cyst wall revealing fibrous connective tissue without lining cell (H and E, ×200)

Figure 3

T2-weighted sagittal MRI images at 14-month follow-up after surgery. No recurrent cyst and no evidence of progression of degenerative change in the L3-4 disc were observed