Teaching NeuroImages: Not a typical spinal mass.

A 20-year-old woman presented with subacute progressive lower extremity weakness and spasticity. Examination findings were consistent with Brown-Sequard syndrome. Thoracic spine MRI/magnetic resonance angiography showed an intramedullary mass (figure 1). During gross total resection, the mass had a pearlescent appearance, while histopathologic examination was consistent with epidermoid cyst (figure 2).