OBJECTIVE To explore the relationship between the clinical characteristics of acoustic neuroma and the number ofT lymphocytes in tumor tissues.METHODS Clinical data of 65 patients diagnosed with VS were retrospectively collected.Peripheral blood samples of the patients were collected and the number of T lymphocytes were counted by flow cytometry.Immunohistochemistry was carried out with the fresh tumor samples compared with 8 normal cranial nerve controls.The expression level of each immune protein was analyzed its correlation with clinical characters was explored.RESULTS The CD3+,CD4+ and CD8+ T lymphocytes in the peripheral blood are not significantly correlated with clinical data.In the tumor tissues,the number of CD4+ and CD8+ T lymphocytes are much larger than those in normal cranial nerves,and negatively correlated with preoperative hearing.The number of CD8+ T lymphocytes has a negative relationship with postoperative facial nerve function.In addition,CD4 and CD8 expression levels in the tumor samples from patients younger than 40 are much higher than those in elder patients.Foxp3 is not detected in the normal cranial nerves.The number of Foxp3+ T lymphocytes is negatively correlated with preoperative hearing.CONCLUSION The CD4+ and CD8+ T lymphocytes mediated cellular immunity play an important role in the development of acoustic neuroma,as well as the reservation and restoration of nerve function.

Objective To discuss the method as well as effect of hearing restoration for patients with acoustic neuroma (AN) in the only hearing ear.Methods A retrospective study was conducted in three patients with AN in the only hearing ear.Ipsilateral cochlear implantation (CI) was performed in case 1 and contralateral CI was performed in case 2 without tumor resection.In case 3,CI was performed 6 months after tumor removal by the retrosigmoid approach.Dynamic changes in the audiological tests was recorded regularly.Results In case 1 and case 2,no matter which side CI was performed,pure tone average (PTA) was improved clearly,and speech discrimination score (SDS) was slightly increased.In case 3,heating loss was observed after tumor removal.Simultaneous bilateral CI after 12 months was performed in this case.PTA on both sides was largely lower than that before CI,and SDS was slightly improved.With bilateral CI,SDS was improved,especially in noise,compared with unilateral CI on either side.Conclusions For patients with AN in the only hearing ear,CI can significantly improve PTA,and SDS can be slightly increased.Bilateral CI should improve the outcome of hearing restoration compared with unilateral CI.