Intraspinal dermoid and epidermoid cysts: Long-term outcome and risk factors.

Objective: The literature on long-term outcome after resection of intraspinal dermoid and epidermoid tumors is limited. The purpose of this study was to review the progression-free survival (PFS), overall survival (OS), and long-term outcome in a consecutive series of 57 patients with intraspinal dermoid and epidermoid tumors. Design: Retrospective study. Methods: A total of 57 patients who underwent surgery at our institution between 2002 and 2010 were reviewed. Patients outcome were determined using the Japanese Orthopaedic Association score (JOA) and the McCormick score. Results: The follow-up data were 100% complete and the median follow-up time was 9.2 years. Gross total resection was performed in 21 patients (36.84%) and subtotal resection in 36 patients (63.16%). The PFS and OS at 8 years were 78.95% and 100% respectively. A good outcome was observed in 56.14% of patients based on the JOA and McCormick score. The univariate analysis showed that a tumor size of more than 4 cm, subtotal resection and sphincter disturbances were the influencing factors of poor outcome. Conclusion: The gold standard treatment for intraspinal tumors is gross total resection, but the operation needs to protect the remaining nerve function as much as possible and follow-up should be focused on patients with a high risk of poor outcome.