Filum terminale infected epidermoid cysts in pediatric age group; A case series

Background: Epidermoid cysts are rare and account for only 1 % of primary spinal tumors. It's due to inclusion of ectodermal tissue during the third and fourth weeks of gestation. Infected epidermoid cysts are exceedingly rare with very few reports in literature. The clinical presentations include radicular symptoms, motor weakness, sphincteric disturbance, and repeated chemical meningitis. Surgery of this kind of tumor remained a challenge and of a considerable recurrence rate.

Methods: This is a retrospective study reviewing the records of six children who were treated for filum terminale infected epidermoid cysts. All patients underwent microsurgery, and the surgical outcomes were studied through a follow up period of at least 24 months.

Results: All children had a low back dermal sinus with purulent discharge. One child was a recurrent presentation after the previous two surgeries for evacuation of pus collection, and the other five children were operated for the first time. All the six children had an associated neurological deficit; one child presented with active central nervous system infection, and one child had a history of meningitis and admission to hospital prior to our surgery. Regular follow up revealed no recurrence in any of the six patients. The five patients, who presented with motor weakness, showed significant improvement of the motor power with regular post-operative physical therapy.

Conclusion: Epidermoid cysts are rare benign lesions that may lead to significant morbidity when infected. The aim of microsurgical excision is to remove the cyst content and its capsule without inducing or increasing neurological deficit by the aid of intraoperative neuromonitoring and microsurgery techniques.