ABSTRACT
<p><b>OBJECTIVE</b>The aim of this study was to investigate the hearing and facial nerve preservation in the middle fossa approach surgery for the removal of small acoustic tumor (vestibular schwannomas, VS).</p><p><b>METHODS</b>A prospective database was established, and data were retrospectively reviewed. Between January 2004 and February 2013, 13 patients with acoustic tumor underwent surgery via middle fossa approach for hearing preservation. The patients consisted of six men and seven women with a mean age of 48 years. Tumor size ranged from 0.8 cm to 1.5 cm. Hearing loss was categorized as American Academy of Otolaryngology Head and Neck Surgery (AAO-HNS) class A, class B, class C and class D. Facial nerve function was evaluated according to House-Brackmann (HB) Grade I-VI.</p><p><b>RESULTS</b>Gross-total resection was accomplished in 12 of 13 patients. Preoperative hearing as class A in ten, class B in two, and class C in one patient respectively. Postoperatively, hearing was graded as class A in eight patients, class B in 3, and class C in 2 patients. Facial nerve function was House-Brackmann (HB) grade I in twelve patients, grade II in one patient preoperatively. Postoperatively, facial nerve function was HB Grade I in twelve patients and Grade III in one patient. The overall hearing preservation rate was at least 80% (8/10) and HB Grade I facial nerve outcome of 100% (12/12) . All cases were followed up for 0.5 to 5 years, no complications were observed.</p><p><b>CONCLUSIONS</b>The middle fossa approach for the resection of small VS with hearing preservation is a viable and relatively option. It should be considered among the various options available for the management of small and growing VS.</p>
Subject(s)
Adult , Female , Humans , Male , Middle Aged , Cranial Fossa, Middle , General Surgery , Facial Nerve , Physiology , General Surgery , Neuroma, Acoustic , General Surgery , Retrospective Studies , Treatment OutcomeABSTRACT
<p><b>OBJECTIVE</b>To investigate the impact of S518 phosphorylation in Merlin on the interaction with CD44 in vestibular schwannoma and the tumor growth.</p><p><b>METHODS</b>Thirty-five samples of vestibular schwannoma were identified by pathology. Immunohistopathology and western blot were employed to analyze the expression and localization of S518 phosphorylated Merlin in the tumor tissues. Nerve tissues that were collected during other surgical operation were used as control. The expression level of S518 phosphorylated Merlin was compared with clinical stages, tumor size, clinical course and cystic degeneration. Immunoprecipitation was used to evaluate the impact of S518 phosphorylation in Merlin on the interaction with CD44.</p><p><b>RESULTS</b>In vestibular schwannoma, Merlin was phosphorylated at S518 and demonstrated perinuclear localization. The S518 phosphorylation level was much lower in the normal control nerve tissues than that in vestibular schwannoma tissues. There was no correlation between the phosphorylation level on Merlin and clinical stages, tumor size, clinical course and cystic degeneration. The S518 phosphorylated Merlin bound CD44 was higher than wild-type Merlin bound CD44 in vestibular schwannoma tissues.</p><p><b>CONCLUSIONS</b>The affinity of Merlin to CD44 was increased after phosphorylation at S518. Different cellular biological results might be triggered through binding to wild type Merlin and S518 phosphorylated Merlin.</p>
Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , Genes, Neurofibromatosis 2 , Hyaluronan Receptors , Genetics , Metabolism , Neoplasm Staging , Neurofibromin 2 , Genetics , Metabolism , Neuroma, Acoustic , Genetics , Metabolism , Pathology , PhosphorylationABSTRACT
<p><b>OBJECTIVE</b>To clarify the expression and subcellular localization of merlin in vestibular schwannoma.</p><p><b>METHODS</b>Fifty four paraffin embedded vestibular schwannoma samples confirmed by pathology after resection were included in the study. The expression of merlin in vestibular schwannoma was analyzed by immunohistochemistry. Nerve tissues that were resected during surgical treatment for trigeminal neuralgia and Meniere's disease were used as control. Western blotting was used to analyze the electrophoresis migration of merlin in the acoustic neuroma. Image analysis was used to calculate the positive expression percentage of merlin in each individual. The expression percentage of merlin in the tumor tissue was compared with age and gender of the patients, clinical course of the tumor, tumor growth index, tumor diameter and clinical stage.</p><p><b>RESULTS</b>Merlin was expressed in 0 to 87.5% of the cells in vestibular schwannoma tissue with a mean of (46.66 +/- 5.75)%. There was a negative correlation between merlin expression percentage and tumor growth index. There were no correlations between merlin expression percentage and the age, gender, tumor diameter and clinical stage. There exists a difference for the location of merlin, mainly in the nucleus and perinucleus. There was also a cytoplasmic location. Merlin in the tumor tissue was shown by western blot to be in 65000 and 125000 positions.</p><p><b>CONCLUSIONS</b>Merlin was expressed in vestibular schwannoma tissue, with a different intra-cellular location. Merlin might also exist as a complex with other proteins in the tumor tissue.</p>