Isolated thoracic (D5) intramedullary epidermoid cyst without spinal dysraphism: A rare case report.

Spinal epidermoid cyst, congenital or acquired, is mainly congenital associated with spinal dysraphism, rarely in isolation. Intramedullary epidermoid cysts (IECs) are rare with less than 60 cases reported so far; isolated variety (i.e., without spinal dysraphism) is still rarer. Complete microsurgical excision is the dictum of surgical treatment. A 14-year-old boy presented with 4-month history of upper backache accompanied with progressive descending paresthesia with paraparesis with early bladder and bowel involvement. His condition deteriorated rapidly making him bedridden. Neurological examination revealed upper thoracic myeloradiculopathy probably of neoplastic origin with sensory localization to D5 spinal level. Digital X-ray revealed no feature suggestive of spinal dysraphism. Contrast magnetic resonance imaging (MRI) characteristics clinched the presumptive diagnosis. Near-total microsurgical excision was done leaving behind a small part of the calcified capsule densely adhered to cord. Histopathological features were confirmative of an epidermoid cyst. Postoperatively, he improved significantly with a gain of motor power sufficient to walk without support within a span of 6 months. Spinal IECs, without any specific clinical presentation, are often diagnosed based upon intraoperative and histopathological findings, however early diagnosis is possible on complete MRI valuation. Complete microsurgical excision, resulting in cessation of clinical progression and remission of symptoms, has to be limited to sub-total or near-total excision if cyst is adherent to cord or its confines.