Dorsal Spinal Intradural Intramedullary Epidermoid Cyst: A Rare Case Report and Review of Literature

Epidermoid cysts are commonly seen intracranial lesions but their occurrence in the spine is rare. They account for <1% of all the benign tumors of the spine. These are benign epithelial-lined cysts filled with keratin. They are classified into two types: congenital or acquired. Congenital epidermoid cysts are more commonly associated with spinal dysraphic states such as syringomyelia, dermal sinus and spina bifida whereas the acquired cysts are associated with repeated lumbar punctures. Based on the location, they can be extradural, intradural, extramedullary, or intramedullary. Most of the epidermoids are intradural extramedullary. Intramedullary epidermoid cysts are very uncommon. We report a case of a 6-year-old female patient with dorsal epidermoid cyst with neurological deficits. Magnetic resonance imaging of the spine showed a well-defined lesion from D9 to D12 which was hypointense on T1W1 and heterogeneously hyperintense on T2W2. Surgery was performed to excise the lesion and to decompress the spinal cord. Histopathological examination of the excised lesion confirmed it as an epidermoid cyst.