Cerebellopontine angle epidermoid cyst presenting with only trigeminal neuralgia: A retrospective study at the single-center in Vietnam

Objective: To assess the influence of clinical and imaging characteristics on the outcome of microsurgery treatment for cerebellopontine angle (CPA) epidermoid cyst (EC) presenting only with trigeminal neuralgia (TN). Methods: A retrospective observational study describing 42 cases of CPA epidermoid cyst presenting only with TN n CPA for 10 years from 2011 to 2021 with the mean follow-up period was 37 months (range, 6–60 months). This study is the largest research with a long follow-up period reported so far worldwide for ECs with only TN symptom. We analyzed the clinical-radiological records of all the patients who met the rigorous requirements to find the distinct features of these tumors. Results: The mean age was 40.1 ± 4.7 years. The time from symptom onset to surgery was 8.6 ± 3.9 months. Symptoms of multiple branches of the 5th nerve appeared in 71.4 %, the most common was V2V3 accounting for 42.9 %. Most of the tumors were located limited in the CPA, accounting for 66.7 %. Total resection reached 90.5 %. The effectiveness of pain relief of microsurgery reached 97.6 %, Barrow Neurological Institute (BNI) score I reached 73.8 % and pain relief was 23.8 %. The postoperative neurologic deficit was 14.3 %. Conclusion: CPA epidermoid cysts presenting with TN as the sole symptom have favorable characteristics for total removing the tumor compared with other tumors in the remaining group. Total removing the tumor with the support of continuous intraoperative electromyography monitoring and decompressing the 5th nerve was ideal; it will not only increase the symptom improvement but also have a low rate of postoperative complications.