Teaching NeuroImages: A Ruptured Lumbar Disc Mimicking Spinal Tumor

A 47-year-old healthy man presented with intermittent low back pain radiating to the left calf; within 1 month, the pain worsened at night and disturbed his sleep. Examination showed paresthesia in left lateral calf, weakness in left ankle plantarflexion, and decreased ankle reflex. Neuroimaging revealed near-total obliteration of the spinal canal by a 2 × 1.2 cm nodule at L5-S1 level with ring enhancement under gadolinium-enhanced MRI (figure 1). The patient underwent surgery for a presumed spinal tumor. The intraoperative and pathologic findings revealed ruptured intervertebral disc without neoplasm (figure 2). The clinical presentation and image characteristics of a large ruptured disc can mimic a spinal tumor.1,2