A rare isolated intradural extramedullary epidermoid cyst of the thoracic spine: A case report and literature review

Spinal epidermoid cysts are rare, benign, slow-growing lesions commonly located in the lumbosacral region. They are commonly intradural and extramedullary. Thoracic spine epidermoid cysts are relatively rare and commonly intradural intramedullary, with a reported incidence of 0.8 %. A 59-year-old female presented with gait instability and bilateral lower limb weakness for two months duration. MRI revealed an isolated intradural extramedullary (IDEM) epidermoid cyst at the T9-T10 level, which was maintained successfully by complete surgical excision with a good functional outcome. Isolated IDEM epidermoid cysts of the thoracic spine are relatively rare. Proper radiological evaluation using MRI with special sequences might be required to differentiate from other common spinal cystic lesions. Proper preoperative localisation of the cyst in the subarachnoid compartments should be confirmed to ensure safe and complete cyst removal and avoid recurrence.