Thoracic spinal Pantopaque cyst and associated syrinx resulting in progressive spastic paraparesis: case report.

Objective and Importance: We describe a unique presentation of a thoracic spinal Pantopaque cyst. Although Pantopaque is no longer used, sequelae of its long-term use may continue to surface.
Clinical Presentation: Our patient presented to the emergency room with 4 months of progressive lower extremity numbness, spasticity, and incontinence and a 2-day history of left upper extremity dysesthesias. Magnetic resonance imaging at admission revealed a C7-T10 syrinx and an intrathecal extramedullary mass to the right of the spinal cord at T10-T11.
Intervention: Radiographic evidence led to the initial diagnosis of hemangioblastoma. The results of a critical analysis of the preoperative studies caused us to suspect a Pantopaque cyst. This suspicion was confirmed at the time of surgery, when a cyst filled with contrast medium was revealed. T9-T11 laminectomies were performed, allowing for a 5-cm dural opening. The cyst was aspirated and excised, and then the syrinx was decompressed.
Conclusion: Our patient experienced significant sensory and motor improvement postoperatively. We present a previously undescribed complication of one of the most commonly used contrast media, Pantopaque. Despite its replacement with newer agents, it may continue to play a significant role in the pathological presentation of patients in whom it was previously used.