Iatrogenic intraspinal epidermoid cyst.

Epidermoid cyst is generally regarded as congenital disease, and commonly related to other congenital spinal anomalies. However, it also develops iatrogenically. We report one rare case of epidermoid cyst that we experineced among intradural extramedullary tumors. A 21-year-old female patient was admitted to the hospital due to low back pain with radiating pain into a right lower extremity that initiated about a month ago. She complained sensory lose and motor weakness (grade 4+) on her right extremity as well as urinary dysfunction and sphincter dysfunction. She had a lumbar puncture three times due to Pneumococcal meningitis when she was 13 years old. The well-circumscribed intradural extramedullary mass of 1.8×1.6×4 cm size was found on the L4-5 in a magnetic resonance image. Gross total tumor removal was garried out after the total laminectomy L5 and partial laminectomy L4. The tumor mass was gray-colored and so fragile that it was easy to be removed. The histological diagnosis confirmed epidermoid cyst without malignancy. After the operation, the patient progressively showed remarkable neurological recovery. In this case, the cause of epidermoid cyst is considered iatrogenic concerning history of several times of lumbar puncture as meningitis.